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      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 2007 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #pragma ident	"@(#)vdev.c	1.33	07/11/27 SMI"
     28 
     29 #include <sys/zfs_context.h>
     30 #include <sys/fm/fs/zfs.h>
     31 #include <sys/spa.h>
     32 #include <sys/spa_impl.h>
     33 #include <sys/dmu.h>
     34 #include <sys/dmu_tx.h>
     35 #include <sys/vdev_impl.h>
     36 #include <sys/uberblock_impl.h>
     37 #include <sys/metaslab.h>
     38 #include <sys/metaslab_impl.h>
     39 #include <sys/space_map.h>
     40 #include <sys/zio.h>
     41 #include <sys/zap.h>
     42 #include <sys/fs/zfs.h>
     43 
     44 /*
     45  * Virtual device management.
     46  */
     47 
     48 static vdev_ops_t *vdev_ops_table[] = {
     49 	&vdev_root_ops,
     50 	&vdev_raidz_ops,
     51 	&vdev_mirror_ops,
     52 	&vdev_replacing_ops,
     53 	&vdev_spare_ops,
     54 	&vdev_disk_ops,
     55 	&vdev_file_ops,
     56 	&vdev_missing_ops,
     57 	NULL
     58 };
     59 
     60 /* maximum scrub/resilver I/O queue */
     61 int zfs_scrub_limit = 70;
     62 
     63 /*
     64  * Given a vdev type, return the appropriate ops vector.
     65  */
     66 static vdev_ops_t *
     67 vdev_getops(const char *type)
     68 {
     69 	vdev_ops_t *ops, **opspp;
     70 
     71 	for (opspp = vdev_ops_table; (ops = *opspp) != NULL; opspp++)
     72 		if (strcmp(ops->vdev_op_type, type) == 0)
     73 			break;
     74 
     75 	return (ops);
     76 }
     77 
     78 /*
     79  * Default asize function: return the MAX of psize with the asize of
     80  * all children.  This is what's used by anything other than RAID-Z.
     81  */
     82 uint64_t
     83 vdev_default_asize(vdev_t *vd, uint64_t psize)
     84 {
     85 	uint64_t asize = P2ROUNDUP(psize, 1ULL << vd->vdev_top->vdev_ashift);
     86 	uint64_t csize;
     87 	uint64_t c;
     88 
     89 	for (c = 0; c < vd->vdev_children; c++) {
     90 		csize = vdev_psize_to_asize(vd->vdev_child[c], psize);
     91 		asize = MAX(asize, csize);
     92 	}
     93 
     94 	return (asize);
     95 }
     96 
     97 /*
     98  * Get the replaceable or attachable device size.
     99  * If the parent is a mirror or raidz, the replaceable size is the minimum
    100  * psize of all its children. For the rest, just return our own psize.
    101  *
    102  * e.g.
    103  *			psize	rsize
    104  * root			-	-
    105  *	mirror/raidz	-	-
    106  *	    disk1	20g	20g
    107  *	    disk2 	40g	20g
    108  *	disk3 		80g	80g
    109  */
    110 uint64_t
    111 vdev_get_rsize(vdev_t *vd)
    112 {
    113 	vdev_t *pvd, *cvd;
    114 	uint64_t c, rsize;
    115 
    116 	pvd = vd->vdev_parent;
    117 
    118 	/*
    119 	 * If our parent is NULL or the root, just return our own psize.
    120 	 */
    121 	if (pvd == NULL || pvd->vdev_parent == NULL)
    122 		return (vd->vdev_psize);
    123 
    124 	rsize = 0;
    125 
    126 	for (c = 0; c < pvd->vdev_children; c++) {
    127 		cvd = pvd->vdev_child[c];
    128 		rsize = MIN(rsize - 1, cvd->vdev_psize - 1) + 1;
    129 	}
    130 
    131 	return (rsize);
    132 }
    133 
    134 vdev_t *
    135 vdev_lookup_top(spa_t *spa, uint64_t vdev)
    136 {
    137 	vdev_t *rvd = spa->spa_root_vdev;
    138 
    139 	ASSERT(spa_config_held(spa, RW_READER) ||
    140 	    curthread == spa->spa_scrub_thread);
    141 
    142 	if (vdev < rvd->vdev_children)
    143 		return (rvd->vdev_child[vdev]);
    144 
    145 	return (NULL);
    146 }
    147 
    148 vdev_t *
    149 vdev_lookup_by_guid(vdev_t *vd, uint64_t guid)
    150 {
    151 	int c;
    152 	vdev_t *mvd;
    153 
    154 	if (vd->vdev_guid == guid)
    155 		return (vd);
    156 
    157 	for (c = 0; c < vd->vdev_children; c++)
    158 		if ((mvd = vdev_lookup_by_guid(vd->vdev_child[c], guid)) !=
    159 		    NULL)
    160 			return (mvd);
    161 
    162 	return (NULL);
    163 }
    164 
    165 void
    166 vdev_add_child(vdev_t *pvd, vdev_t *cvd)
    167 {
    168 	size_t oldsize, newsize;
    169 	uint64_t id = cvd->vdev_id;
    170 	vdev_t **newchild;
    171 
    172 	ASSERT(spa_config_held(cvd->vdev_spa, RW_WRITER));
    173 	ASSERT(cvd->vdev_parent == NULL);
    174 
    175 	cvd->vdev_parent = pvd;
    176 
    177 	if (pvd == NULL)
    178 		return;
    179 
    180 	ASSERT(id >= pvd->vdev_children || pvd->vdev_child[id] == NULL);
    181 
    182 	oldsize = pvd->vdev_children * sizeof (vdev_t *);
    183 	pvd->vdev_children = MAX(pvd->vdev_children, id + 1);
    184 	newsize = pvd->vdev_children * sizeof (vdev_t *);
    185 
    186 	newchild = kmem_zalloc(newsize, KM_SLEEP);
    187 	if (pvd->vdev_child != NULL) {
    188 		bcopy(pvd->vdev_child, newchild, oldsize);
    189 		kmem_free(pvd->vdev_child, oldsize);
    190 	}
    191 
    192 	pvd->vdev_child = newchild;
    193 	pvd->vdev_child[id] = cvd;
    194 
    195 	cvd->vdev_top = (pvd->vdev_top ? pvd->vdev_top: cvd);
    196 	ASSERT(cvd->vdev_top->vdev_parent->vdev_parent == NULL);
    197 
    198 	/*
    199 	 * Walk up all ancestors to update guid sum.
    200 	 */
    201 	for (; pvd != NULL; pvd = pvd->vdev_parent)
    202 		pvd->vdev_guid_sum += cvd->vdev_guid_sum;
    203 
    204 	if (cvd->vdev_ops->vdev_op_leaf)
    205 		cvd->vdev_spa->spa_scrub_maxinflight += zfs_scrub_limit;
    206 }
    207 
    208 void
    209 vdev_remove_child(vdev_t *pvd, vdev_t *cvd)
    210 {
    211 	int c;
    212 	uint_t id = cvd->vdev_id;
    213 
    214 	ASSERT(cvd->vdev_parent == pvd);
    215 
    216 	if (pvd == NULL)
    217 		return;
    218 
    219 	ASSERT(id < pvd->vdev_children);
    220 	ASSERT(pvd->vdev_child[id] == cvd);
    221 
    222 	pvd->vdev_child[id] = NULL;
    223 	cvd->vdev_parent = NULL;
    224 
    225 	for (c = 0; c < pvd->vdev_children; c++)
    226 		if (pvd->vdev_child[c])
    227 			break;
    228 
    229 	if (c == pvd->vdev_children) {
    230 		kmem_free(pvd->vdev_child, c * sizeof (vdev_t *));
    231 		pvd->vdev_child = NULL;
    232 		pvd->vdev_children = 0;
    233 	}
    234 
    235 	/*
    236 	 * Walk up all ancestors to update guid sum.
    237 	 */
    238 	for (; pvd != NULL; pvd = pvd->vdev_parent)
    239 		pvd->vdev_guid_sum -= cvd->vdev_guid_sum;
    240 
    241 	if (cvd->vdev_ops->vdev_op_leaf)
    242 		cvd->vdev_spa->spa_scrub_maxinflight -= zfs_scrub_limit;
    243 }
    244 
    245 /*
    246  * Remove any holes in the child array.
    247  */
    248 void
    249 vdev_compact_children(vdev_t *pvd)
    250 {
    251 	vdev_t **newchild, *cvd;
    252 	int oldc = pvd->vdev_children;
    253 	int newc, c;
    254 
    255 	ASSERT(spa_config_held(pvd->vdev_spa, RW_WRITER));
    256 
    257 	for (c = newc = 0; c < oldc; c++)
    258 		if (pvd->vdev_child[c])
    259 			newc++;
    260 
    261 	newchild = kmem_alloc(newc * sizeof (vdev_t *), KM_SLEEP);
    262 
    263 	for (c = newc = 0; c < oldc; c++) {
    264 		if ((cvd = pvd->vdev_child[c]) != NULL) {
    265 			newchild[newc] = cvd;
    266 			cvd->vdev_id = newc++;
    267 		}
    268 	}
    269 
    270 	kmem_free(pvd->vdev_child, oldc * sizeof (vdev_t *));
    271 	pvd->vdev_child = newchild;
    272 	pvd->vdev_children = newc;
    273 }
    274 
    275 /*
    276  * Allocate and minimally initialize a vdev_t.
    277  */
    278 static vdev_t *
    279 vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid, vdev_ops_t *ops)
    280 {
    281 	vdev_t *vd;
    282 
    283 	vd = kmem_zalloc(sizeof (vdev_t), KM_SLEEP);
    284 
    285 	if (spa->spa_root_vdev == NULL) {
    286 		ASSERT(ops == &vdev_root_ops);
    287 		spa->spa_root_vdev = vd;
    288 	}
    289 
    290 	if (guid == 0) {
    291 		if (spa->spa_root_vdev == vd) {
    292 			/*
    293 			 * The root vdev's guid will also be the pool guid,
    294 			 * which must be unique among all pools.
    295 			 */
    296 			while (guid == 0 || spa_guid_exists(guid, 0))
    297 				guid = spa_get_random(-1ULL);
    298 		} else {
    299 			/*
    300 			 * Any other vdev's guid must be unique within the pool.
    301 			 */
    302 			while (guid == 0 ||
    303 			    spa_guid_exists(spa_guid(spa), guid))
    304 				guid = spa_get_random(-1ULL);
    305 		}
    306 		ASSERT(!spa_guid_exists(spa_guid(spa), guid));
    307 	}
    308 
    309 	vd->vdev_spa = spa;
    310 	vd->vdev_id = id;
    311 	vd->vdev_guid = guid;
    312 	vd->vdev_guid_sum = guid;
    313 	vd->vdev_ops = ops;
    314 	vd->vdev_state = VDEV_STATE_CLOSED;
    315 
    316 	mutex_init(&vd->vdev_dtl_lock, NULL, MUTEX_DEFAULT, NULL);
    317 	mutex_init(&vd->vdev_stat_lock, NULL, MUTEX_DEFAULT, NULL);
    318 	space_map_create(&vd->vdev_dtl_map, 0, -1ULL, 0, &vd->vdev_dtl_lock);
    319 	space_map_create(&vd->vdev_dtl_scrub, 0, -1ULL, 0, &vd->vdev_dtl_lock);
    320 	txg_list_create(&vd->vdev_ms_list,
    321 	    offsetof(struct metaslab, ms_txg_node));
    322 	txg_list_create(&vd->vdev_dtl_list,
    323 	    offsetof(struct vdev, vdev_dtl_node));
    324 	vd->vdev_stat.vs_timestamp = gethrtime();
    325 	vdev_queue_init(vd);
    326 	vdev_cache_init(vd);
    327 
    328 	return (vd);
    329 }
    330 
    331 /*
    332  * Allocate a new vdev.  The 'alloctype' is used to control whether we are
    333  * creating a new vdev or loading an existing one - the behavior is slightly
    334  * different for each case.
    335  */
    336 int
    337 vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent, uint_t id,
    338     int alloctype)
    339 {
    340 	vdev_ops_t *ops;
    341 	char *type;
    342 	uint64_t guid = 0, islog, nparity;
    343 	vdev_t *vd;
    344 
    345 	ASSERT(spa_config_held(spa, RW_WRITER));
    346 
    347 	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_TYPE, &type) != 0)
    348 		return (EINVAL);
    349 
    350 	if ((ops = vdev_getops(type)) == NULL)
    351 		return (EINVAL);
    352 
    353 	/*
    354 	 * If this is a load, get the vdev guid from the nvlist.
    355 	 * Otherwise, vdev_alloc_common() will generate one for us.
    356 	 */
    357 	if (alloctype == VDEV_ALLOC_LOAD) {
    358 		uint64_t label_id;
    359 
    360 		if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ID, &label_id) ||
    361 		    label_id != id)
    362 			return (EINVAL);
    363 
    364 		if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
    365 			return (EINVAL);
    366 	} else if (alloctype == VDEV_ALLOC_SPARE) {
    367 		if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
    368 			return (EINVAL);
    369 	} else if (alloctype == VDEV_ALLOC_L2CACHE) {
    370 		if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) != 0)
    371 			return (EINVAL);
    372 	}
    373 
    374 	/*
    375 	 * The first allocated vdev must be of type 'root'.
    376 	 */
    377 	if (ops != &vdev_root_ops && spa->spa_root_vdev == NULL)
    378 		return (EINVAL);
    379 
    380 	/*
    381 	 * Determine whether we're a log vdev.
    382 	 */
    383 	islog = 0;
    384 	(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_LOG, &islog);
    385 	if (islog && spa_version(spa) < SPA_VERSION_SLOGS)
    386 		return (ENOTSUP);
    387 
    388 	/*
    389 	 * Set the nparity property for RAID-Z vdevs.
    390 	 */
    391 	nparity = -1ULL;
    392 	if (ops == &vdev_raidz_ops) {
    393 		if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY,
    394 		    &nparity) == 0) {
    395 			/*
    396 			 * Currently, we can only support 2 parity devices.
    397 			 */
    398 			if (nparity == 0 || nparity > 2)
    399 				return (EINVAL);
    400 			/*
    401 			 * Older versions can only support 1 parity device.
    402 			 */
    403 			if (nparity == 2 &&
    404 			    spa_version(spa) < SPA_VERSION_RAID6)
    405 				return (ENOTSUP);
    406 		} else {
    407 			/*
    408 			 * We require the parity to be specified for SPAs that
    409 			 * support multiple parity levels.
    410 			 */
    411 			if (spa_version(spa) >= SPA_VERSION_RAID6)
    412 				return (EINVAL);
    413 			/*
    414 			 * Otherwise, we default to 1 parity device for RAID-Z.
    415 			 */
    416 			nparity = 1;
    417 		}
    418 	} else {
    419 		nparity = 0;
    420 	}
    421 	ASSERT(nparity != -1ULL);
    422 
    423 	vd = vdev_alloc_common(spa, id, guid, ops);
    424 
    425 	vd->vdev_islog = islog;
    426 	vd->vdev_nparity = nparity;
    427 
    428 	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &vd->vdev_path) == 0)
    429 		vd->vdev_path = spa_strdup(vd->vdev_path);
    430 	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_DEVID, &vd->vdev_devid) == 0)
    431 		vd->vdev_devid = spa_strdup(vd->vdev_devid);
    432 	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PHYS_PATH,
    433 	    &vd->vdev_physpath) == 0)
    434 		vd->vdev_physpath = spa_strdup(vd->vdev_physpath);
    435 
    436 	/*
    437 	 * Set the whole_disk property.  If it's not specified, leave the value
    438 	 * as -1.
    439 	 */
    440 	if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
    441 	    &vd->vdev_wholedisk) != 0)
    442 		vd->vdev_wholedisk = -1ULL;
    443 
    444 	/*
    445 	 * Look for the 'not present' flag.  This will only be set if the device
    446 	 * was not present at the time of import.
    447 	 */
    448 	(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT,
    449 	    &vd->vdev_not_present);
    450 
    451 	/*
    452 	 * Get the alignment requirement.
    453 	 */
    454 	(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ASHIFT, &vd->vdev_ashift);
    455 
    456 	/*
    457 	 * If we're a top-level vdev, try to load the allocation parameters.
    458 	 */
    459 	if (parent && !parent->vdev_parent && alloctype == VDEV_ALLOC_LOAD) {
    460 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY,
    461 		    &vd->vdev_ms_array);
    462 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT,
    463 		    &vd->vdev_ms_shift);
    464 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ASIZE,
    465 		    &vd->vdev_asize);
    466 	}
    467 
    468 	/*
    469 	 * If we're a leaf vdev, try to load the DTL object and other state.
    470 	 */
    471 	if (vd->vdev_ops->vdev_op_leaf && alloctype == VDEV_ALLOC_LOAD) {
    472 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DTL,
    473 		    &vd->vdev_dtl.smo_object);
    474 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_OFFLINE,
    475 		    &vd->vdev_offline);
    476 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_UNSPARE,
    477 		    &vd->vdev_unspare);
    478 		/*
    479 		 * When importing a pool, we want to ignore the persistent fault
    480 		 * state, as the diagnosis made on another system may not be
    481 		 * valid in the current context.
    482 		 */
    483 		if (spa->spa_load_state == SPA_LOAD_OPEN) {
    484 			(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_FAULTED,
    485 			    &vd->vdev_faulted);
    486 			(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DEGRADED,
    487 			    &vd->vdev_degraded);
    488 			(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_REMOVED,
    489 			    &vd->vdev_removed);
    490 		}
    491 	}
    492 
    493 	/*
    494 	 * Add ourselves to the parent's list of children.
    495 	 */
    496 	vdev_add_child(parent, vd);
    497 
    498 	*vdp = vd;
    499 
    500 	return (0);
    501 }
    502 
    503 void
    504 vdev_free(vdev_t *vd)
    505 {
    506 	int c;
    507 	spa_t *spa = vd->vdev_spa;
    508 
    509 	/*
    510 	 * vdev_free() implies closing the vdev first.  This is simpler than
    511 	 * trying to ensure complicated semantics for all callers.
    512 	 */
    513 	vdev_close(vd);
    514 
    515 
    516 	ASSERT(!list_link_active(&vd->vdev_dirty_node));
    517 
    518 	/*
    519 	 * Free all children.
    520 	 */
    521 	for (c = 0; c < vd->vdev_children; c++)
    522 		vdev_free(vd->vdev_child[c]);
    523 
    524 	ASSERT(vd->vdev_child == NULL);
    525 	ASSERT(vd->vdev_guid_sum == vd->vdev_guid);
    526 
    527 	/*
    528 	 * Discard allocation state.
    529 	 */
    530 	if (vd == vd->vdev_top)
    531 		vdev_metaslab_fini(vd);
    532 
    533 	ASSERT3U(vd->vdev_stat.vs_space, ==, 0);
    534 	ASSERT3U(vd->vdev_stat.vs_dspace, ==, 0);
    535 	ASSERT3U(vd->vdev_stat.vs_alloc, ==, 0);
    536 
    537 	/*
    538 	 * Remove this vdev from its parent's child list.
    539 	 */
    540 	vdev_remove_child(vd->vdev_parent, vd);
    541 
    542 	ASSERT(vd->vdev_parent == NULL);
    543 
    544 	/*
    545 	 * Clean up vdev structure.
    546 	 */
    547 	vdev_queue_fini(vd);
    548 	vdev_cache_fini(vd);
    549 
    550 	if (vd->vdev_path)
    551 		spa_strfree(vd->vdev_path);
    552 	if (vd->vdev_devid)
    553 		spa_strfree(vd->vdev_devid);
    554 	if (vd->vdev_physpath)
    555 		spa_strfree(vd->vdev_physpath);
    556 
    557 	if (vd->vdev_isspare)
    558 		spa_spare_remove(vd);
    559 	if (vd->vdev_isl2cache)
    560 		spa_l2cache_remove(vd);
    561 
    562 	txg_list_destroy(&vd->vdev_ms_list);
    563 	txg_list_destroy(&vd->vdev_dtl_list);
    564 	mutex_enter(&vd->vdev_dtl_lock);
    565 	space_map_unload(&vd->vdev_dtl_map);
    566 	space_map_destroy(&vd->vdev_dtl_map);
    567 	space_map_vacate(&vd->vdev_dtl_scrub, NULL, NULL);
    568 	space_map_destroy(&vd->vdev_dtl_scrub);
    569 	mutex_exit(&vd->vdev_dtl_lock);
    570 	mutex_destroy(&vd->vdev_dtl_lock);
    571 	mutex_destroy(&vd->vdev_stat_lock);
    572 
    573 	if (vd == spa->spa_root_vdev)
    574 		spa->spa_root_vdev = NULL;
    575 
    576 	kmem_free(vd, sizeof (vdev_t));
    577 }
    578 
    579 /*
    580  * Transfer top-level vdev state from svd to tvd.
    581  */
    582 static void
    583 vdev_top_transfer(vdev_t *svd, vdev_t *tvd)
    584 {
    585 	spa_t *spa = svd->vdev_spa;
    586 	metaslab_t *msp;
    587 	vdev_t *vd;
    588 	int t;
    589 
    590 	ASSERT(tvd == tvd->vdev_top);
    591 
    592 	tvd->vdev_ms_array = svd->vdev_ms_array;
    593 	tvd->vdev_ms_shift = svd->vdev_ms_shift;
    594 	tvd->vdev_ms_count = svd->vdev_ms_count;
    595 
    596 	svd->vdev_ms_array = 0;
    597 	svd->vdev_ms_shift = 0;
    598 	svd->vdev_ms_count = 0;
    599 
    600 	tvd->vdev_mg = svd->vdev_mg;
    601 	tvd->vdev_ms = svd->vdev_ms;
    602 
    603 	svd->vdev_mg = NULL;
    604 	svd->vdev_ms = NULL;
    605 
    606 	if (tvd->vdev_mg != NULL)
    607 		tvd->vdev_mg->mg_vd = tvd;
    608 
    609 	tvd->vdev_stat.vs_alloc = svd->vdev_stat.vs_alloc;
    610 	tvd->vdev_stat.vs_space = svd->vdev_stat.vs_space;
    611 	tvd->vdev_stat.vs_dspace = svd->vdev_stat.vs_dspace;
    612 
    613 	svd->vdev_stat.vs_alloc = 0;
    614 	svd->vdev_stat.vs_space = 0;
    615 	svd->vdev_stat.vs_dspace = 0;
    616 
    617 	for (t = 0; t < TXG_SIZE; t++) {
    618 		while ((msp = txg_list_remove(&svd->vdev_ms_list, t)) != NULL)
    619 			(void) txg_list_add(&tvd->vdev_ms_list, msp, t);
    620 		while ((vd = txg_list_remove(&svd->vdev_dtl_list, t)) != NULL)
    621 			(void) txg_list_add(&tvd->vdev_dtl_list, vd, t);
    622 		if (txg_list_remove_this(&spa->spa_vdev_txg_list, svd, t))
    623 			(void) txg_list_add(&spa->spa_vdev_txg_list, tvd, t);
    624 	}
    625 
    626 	if (list_link_active(&svd->vdev_dirty_node)) {
    627 		vdev_config_clean(svd);
    628 		vdev_config_dirty(tvd);
    629 	}
    630 
    631 	tvd->vdev_deflate_ratio = svd->vdev_deflate_ratio;
    632 	svd->vdev_deflate_ratio = 0;
    633 
    634 	tvd->vdev_islog = svd->vdev_islog;
    635 	svd->vdev_islog = 0;
    636 }
    637 
    638 static void
    639 vdev_top_update(vdev_t *tvd, vdev_t *vd)
    640 {
    641 	int c;
    642 
    643 	if (vd == NULL)
    644 		return;
    645 
    646 	vd->vdev_top = tvd;
    647 
    648 	for (c = 0; c < vd->vdev_children; c++)
    649 		vdev_top_update(tvd, vd->vdev_child[c]);
    650 }
    651 
    652 /*
    653  * Add a mirror/replacing vdev above an existing vdev.
    654  */
    655 vdev_t *
    656 vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops)
    657 {
    658 	spa_t *spa = cvd->vdev_spa;
    659 	vdev_t *pvd = cvd->vdev_parent;
    660 	vdev_t *mvd;
    661 
    662 	ASSERT(spa_config_held(spa, RW_WRITER));
    663 
    664 	mvd = vdev_alloc_common(spa, cvd->vdev_id, 0, ops);
    665 
    666 	mvd->vdev_asize = cvd->vdev_asize;
    667 	mvd->vdev_ashift = cvd->vdev_ashift;
    668 	mvd->vdev_state = cvd->vdev_state;
    669 
    670 	vdev_remove_child(pvd, cvd);
    671 	vdev_add_child(pvd, mvd);
    672 	cvd->vdev_id = mvd->vdev_children;
    673 	vdev_add_child(mvd, cvd);
    674 	vdev_top_update(cvd->vdev_top, cvd->vdev_top);
    675 
    676 	if (mvd == mvd->vdev_top)
    677 		vdev_top_transfer(cvd, mvd);
    678 
    679 	return (mvd);
    680 }
    681 
    682 /*
    683  * Remove a 1-way mirror/replacing vdev from the tree.
    684  */
    685 void
    686 vdev_remove_parent(vdev_t *cvd)
    687 {
    688 	vdev_t *mvd = cvd->vdev_parent;
    689 	vdev_t *pvd = mvd->vdev_parent;
    690 
    691 	ASSERT(spa_config_held(cvd->vdev_spa, RW_WRITER));
    692 
    693 	ASSERT(mvd->vdev_children == 1);
    694 	ASSERT(mvd->vdev_ops == &vdev_mirror_ops ||
    695 	    mvd->vdev_ops == &vdev_replacing_ops ||
    696 	    mvd->vdev_ops == &vdev_spare_ops);
    697 	cvd->vdev_ashift = mvd->vdev_ashift;
    698 
    699 	vdev_remove_child(mvd, cvd);
    700 	vdev_remove_child(pvd, mvd);
    701 	cvd->vdev_id = mvd->vdev_id;
    702 	vdev_add_child(pvd, cvd);
    703 	/*
    704 	 * If we created a new toplevel vdev, then we need to change the child's
    705 	 * vdev GUID to match the old toplevel vdev.  Otherwise, we could have
    706 	 * detached an offline device, and when we go to import the pool we'll
    707 	 * think we have two toplevel vdevs, instead of a different version of
    708 	 * the same toplevel vdev.
    709 	 */
    710 	if (cvd->vdev_top == cvd) {
    711 		pvd->vdev_guid_sum -= cvd->vdev_guid;
    712 		cvd->vdev_guid_sum -= cvd->vdev_guid;
    713 		cvd->vdev_guid = mvd->vdev_guid;
    714 		cvd->vdev_guid_sum += mvd->vdev_guid;
    715 		pvd->vdev_guid_sum += cvd->vdev_guid;
    716 	}
    717 	vdev_top_update(cvd->vdev_top, cvd->vdev_top);
    718 
    719 	if (cvd == cvd->vdev_top)
    720 		vdev_top_transfer(mvd, cvd);
    721 
    722 	ASSERT(mvd->vdev_children == 0);
    723 	vdev_free(mvd);
    724 }
    725 
    726 int
    727 vdev_metaslab_init(vdev_t *vd, uint64_t txg)
    728 {
    729 	spa_t *spa = vd->vdev_spa;
    730 	objset_t *mos = spa->spa_meta_objset;
    731 	metaslab_class_t *mc;
    732 	uint64_t m;
    733 	uint64_t oldc = vd->vdev_ms_count;
    734 	uint64_t newc = vd->vdev_asize >> vd->vdev_ms_shift;
    735 	metaslab_t **mspp;
    736 	int error;
    737 
    738 	if (vd->vdev_ms_shift == 0)	/* not being allocated from yet */
    739 		return (0);
    740 
    741 	dprintf("%s oldc %llu newc %llu\n", vdev_description(vd), oldc, newc);
    742 
    743 	ASSERT(oldc <= newc);
    744 
    745 	if (vd->vdev_islog)
    746 		mc = spa->spa_log_class;
    747 	else
    748 		mc = spa->spa_normal_class;
    749 
    750 	if (vd->vdev_mg == NULL)
    751 		vd->vdev_mg = metaslab_group_create(mc, vd);
    752 
    753 	mspp = kmem_zalloc(newc * sizeof (*mspp), KM_SLEEP);
    754 
    755 	if (oldc != 0) {
    756 		bcopy(vd->vdev_ms, mspp, oldc * sizeof (*mspp));
    757 		kmem_free(vd->vdev_ms, oldc * sizeof (*mspp));
    758 	}
    759 
    760 	vd->vdev_ms = mspp;
    761 	vd->vdev_ms_count = newc;
    762 
    763 	for (m = oldc; m < newc; m++) {
    764 		space_map_obj_t smo = { 0, 0, 0 };
    765 		if (txg == 0) {
    766 			uint64_t object = 0;
    767 			error = dmu_read(mos, vd->vdev_ms_array,
    768 			    m * sizeof (uint64_t), sizeof (uint64_t), &object);
    769 			if (error)
    770 				return (error);
    771 			if (object != 0) {
    772 				dmu_buf_t *db;
    773 				error = dmu_bonus_hold(mos, object, FTAG, &db);
    774 				if (error)
    775 					return (error);
    776 				ASSERT3U(db->db_size, >=, sizeof (smo));
    777 				bcopy(db->db_data, &smo, sizeof (smo));
    778 				ASSERT3U(smo.smo_object, ==, object);
    779 				dmu_buf_rele(db, FTAG);
    780 			}
    781 		}
    782 		vd->vdev_ms[m] = metaslab_init(vd->vdev_mg, &smo,
    783 		    m << vd->vdev_ms_shift, 1ULL << vd->vdev_ms_shift, txg);
    784 	}
    785 
    786 	return (0);
    787 }
    788 
    789 void
    790 vdev_metaslab_fini(vdev_t *vd)
    791 {
    792 	uint64_t m;
    793 	uint64_t count = vd->vdev_ms_count;
    794 
    795 	if (vd->vdev_ms != NULL) {
    796 		for (m = 0; m < count; m++)
    797 			if (vd->vdev_ms[m] != NULL)
    798 				metaslab_fini(vd->vdev_ms[m]);
    799 		kmem_free(vd->vdev_ms, count * sizeof (metaslab_t *));
    800 		vd->vdev_ms = NULL;
    801 	}
    802 }
    803 
    804 int
    805 vdev_probe(vdev_t *vd)
    806 {
    807 	if (vd == NULL)
    808 		return (EINVAL);
    809 
    810 	/*
    811 	 * Right now we only support status checks on the leaf vdevs.
    812 	 */
    813 	if (vd->vdev_ops->vdev_op_leaf)
    814 		return (vd->vdev_ops->vdev_op_probe(vd));
    815 
    816 	return (0);
    817 }
    818 
    819 /*
    820  * Prepare a virtual device for access.
    821  */
    822 int
    823 vdev_open(vdev_t *vd)
    824 {
    825 	int error;
    826 	int c;
    827 	uint64_t osize = 0;
    828 	uint64_t asize, psize;
    829 	uint64_t ashift = 0;
    830 
    831 	ASSERT(vd->vdev_state == VDEV_STATE_CLOSED ||
    832 	    vd->vdev_state == VDEV_STATE_CANT_OPEN ||
    833 	    vd->vdev_state == VDEV_STATE_OFFLINE);
    834 
    835 	if (vd->vdev_fault_mode == VDEV_FAULT_COUNT)
    836 		vd->vdev_fault_arg >>= 1;
    837 	else
    838 		vd->vdev_fault_mode = VDEV_FAULT_NONE;
    839 
    840 	vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
    841 
    842 	if (!vd->vdev_removed && vd->vdev_faulted) {
    843 		ASSERT(vd->vdev_children == 0);
    844 		vdev_set_state(vd, B_TRUE, VDEV_STATE_FAULTED,
    845 		    VDEV_AUX_ERR_EXCEEDED);
    846 		return (ENXIO);
    847 	} else if (vd->vdev_offline) {
    848 		ASSERT(vd->vdev_children == 0);
    849 		vdev_set_state(vd, B_TRUE, VDEV_STATE_OFFLINE, VDEV_AUX_NONE);
    850 		return (ENXIO);
    851 	}
    852 
    853 	error = vd->vdev_ops->vdev_op_open(vd, &osize, &ashift);
    854 
    855 	if (zio_injection_enabled && error == 0)
    856 		error = zio_handle_device_injection(vd, ENXIO);
    857 
    858 	if (error) {
    859 		if (vd->vdev_removed &&
    860 		    vd->vdev_stat.vs_aux != VDEV_AUX_OPEN_FAILED)
    861 			vd->vdev_removed = B_FALSE;
    862 
    863 		vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
    864 		    vd->vdev_stat.vs_aux);
    865 		return (error);
    866 	}
    867 
    868 	vd->vdev_removed = B_FALSE;
    869 
    870 	if (vd->vdev_degraded) {
    871 		ASSERT(vd->vdev_children == 0);
    872 		vdev_set_state(vd, B_TRUE, VDEV_STATE_DEGRADED,
    873 		    VDEV_AUX_ERR_EXCEEDED);
    874 	} else {
    875 		vd->vdev_state = VDEV_STATE_HEALTHY;
    876 	}
    877 
    878 	for (c = 0; c < vd->vdev_children; c++)
    879 		if (vd->vdev_child[c]->vdev_state != VDEV_STATE_HEALTHY) {
    880 			vdev_set_state(vd, B_TRUE, VDEV_STATE_DEGRADED,
    881 			    VDEV_AUX_NONE);
    882 			break;
    883 		}
    884 
    885 	osize = P2ALIGN(osize, (uint64_t)sizeof (vdev_label_t));
    886 
    887 	if (vd->vdev_children == 0) {
    888 		if (osize < SPA_MINDEVSIZE) {
    889 			vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
    890 			    VDEV_AUX_TOO_SMALL);
    891 			return (EOVERFLOW);
    892 		}
    893 		psize = osize;
    894 		asize = osize - (VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE);
    895 	} else {
    896 		if (vd->vdev_parent != NULL && osize < SPA_MINDEVSIZE -
    897 		    (VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE)) {
    898 			vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
    899 			    VDEV_AUX_TOO_SMALL);
    900 			return (EOVERFLOW);
    901 		}
    902 		psize = 0;
    903 		asize = osize;
    904 	}
    905 
    906 	vd->vdev_psize = psize;
    907 
    908 	if (vd->vdev_asize == 0) {
    909 		/*
    910 		 * This is the first-ever open, so use the computed values.
    911 		 * For testing purposes, a higher ashift can be requested.
    912 		 */
    913 		vd->vdev_asize = asize;
    914 		vd->vdev_ashift = MAX(ashift, vd->vdev_ashift);
    915 	} else {
    916 		/*
    917 		 * Make sure the alignment requirement hasn't increased.
    918 		 */
    919 		if (ashift > vd->vdev_top->vdev_ashift) {
    920 			vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
    921 			    VDEV_AUX_BAD_LABEL);
    922 			return (EINVAL);
    923 		}
    924 
    925 		/*
    926 		 * Make sure the device hasn't shrunk.
    927 		 */
    928 		if (asize < vd->vdev_asize) {
    929 			vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
    930 			    VDEV_AUX_BAD_LABEL);
    931 			return (EINVAL);
    932 		}
    933 
    934 		/*
    935 		 * If all children are healthy and the asize has increased,
    936 		 * then we've experienced dynamic LUN growth.
    937 		 */
    938 		if (vd->vdev_state == VDEV_STATE_HEALTHY &&
    939 		    asize > vd->vdev_asize) {
    940 			vd->vdev_asize = asize;
    941 		}
    942 	}
    943 
    944 	/*
    945 	 * Ensure we can issue some IO before declaring the
    946 	 * vdev open for business.
    947 	 */
    948 	error = vdev_probe(vd);
    949 	if (error) {
    950 		vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
    951 		    VDEV_AUX_OPEN_FAILED);
    952 		return (error);
    953 	}
    954 
    955 	/*
    956 	 * If this is a top-level vdev, compute the raidz-deflation
    957 	 * ratio.  Note, we hard-code in 128k (1<<17) because it is the
    958 	 * current "typical" blocksize.  Even if SPA_MAXBLOCKSIZE
    959 	 * changes, this algorithm must never change, or we will
    960 	 * inconsistently account for existing bp's.
    961 	 */
    962 	if (vd->vdev_top == vd) {
    963 		vd->vdev_deflate_ratio = (1<<17) /
    964 		    (vdev_psize_to_asize(vd, 1<<17) >> SPA_MINBLOCKSHIFT);
    965 	}
    966 
    967 	/*
    968 	 * This allows the ZFS DE to close cases appropriately.  If a device
    969 	 * goes away and later returns, we want to close the associated case.
    970 	 * But it's not enough to simply post this only when a device goes from
    971 	 * CANT_OPEN -> HEALTHY.  If we reboot the system and the device is
    972 	 * back, we also need to close the case (otherwise we will try to replay
    973 	 * it).  So we have to post this notifier every time.  Since this only
    974 	 * occurs during pool open or error recovery, this should not be an
    975 	 * issue.
    976 	 */
    977 	zfs_post_ok(vd->vdev_spa, vd);
    978 
    979 	return (0);
    980 }
    981 
    982 /*
    983  * Called once the vdevs are all opened, this routine validates the label
    984  * contents.  This needs to be done before vdev_load() so that we don't
    985  * inadvertently do repair I/Os to the wrong device.
    986  *
    987  * This function will only return failure if one of the vdevs indicates that it
    988  * has since been destroyed or exported.  This is only possible if
    989  * /etc/zfs/zpool.cache was readonly at the time.  Otherwise, the vdev state
    990  * will be updated but the function will return 0.
    991  */
    992 int
    993 vdev_validate(vdev_t *vd)
    994 {
    995 	spa_t *spa = vd->vdev_spa;
    996 	int c;
    997 	nvlist_t *label;
    998 	uint64_t guid;
    999 	uint64_t state;
   1000 
   1001 	for (c = 0; c < vd->vdev_children; c++)
   1002 		if (vdev_validate(vd->vdev_child[c]) != 0)
   1003 			return (EBADF);
   1004 
   1005 	/*
   1006 	 * If the device has already failed, or was marked offline, don't do
   1007 	 * any further validation.  Otherwise, label I/O will fail and we will
   1008 	 * overwrite the previous state.
   1009 	 */
   1010 	if (vd->vdev_ops->vdev_op_leaf && !vdev_is_dead(vd)) {
   1011 
   1012 		if ((label = vdev_label_read_config(vd)) == NULL) {
   1013 			vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
   1014 			    VDEV_AUX_BAD_LABEL);
   1015 			return (0);
   1016 		}
   1017 
   1018 		if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_GUID,
   1019 		    &guid) != 0 || guid != spa_guid(spa)) {
   1020 			vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
   1021 			    VDEV_AUX_CORRUPT_DATA);
   1022 			nvlist_free(label);
   1023 			return (0);
   1024 		}
   1025 
   1026 		if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID,
   1027 		    &guid) != 0 || guid != vd->vdev_guid) {
   1028 			vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
   1029 			    VDEV_AUX_CORRUPT_DATA);
   1030 			nvlist_free(label);
   1031 			return (0);
   1032 		}
   1033 
   1034 		if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE,
   1035 		    &state) != 0) {
   1036 			vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
   1037 			    VDEV_AUX_CORRUPT_DATA);
   1038 			nvlist_free(label);
   1039 			return (0);
   1040 		}
   1041 
   1042 		nvlist_free(label);
   1043 
   1044 		if (spa->spa_load_state == SPA_LOAD_OPEN &&
   1045 		    state != POOL_STATE_ACTIVE)
   1046 			return (EBADF);
   1047 	}
   1048 
   1049 	/*
   1050 	 * If we were able to open and validate a vdev that was previously
   1051 	 * marked permanently unavailable, clear that state now.
   1052 	 */
   1053 	if (vd->vdev_not_present)
   1054 		vd->vdev_not_present = 0;
   1055 
   1056 	return (0);
   1057 }
   1058 
   1059 /*
   1060  * Close a virtual device.
   1061  */
   1062 void
   1063 vdev_close(vdev_t *vd)
   1064 {
   1065 	vd->vdev_ops->vdev_op_close(vd);
   1066 
   1067 	vdev_cache_purge(vd);
   1068 
   1069 	/*
   1070 	 * We record the previous state before we close it, so  that if we are
   1071 	 * doing a reopen(), we don't generate FMA ereports if we notice that
   1072 	 * it's still faulted.
   1073 	 */
   1074 	vd->vdev_prevstate = vd->vdev_state;
   1075 
   1076 	if (vd->vdev_offline)
   1077 		vd->vdev_state = VDEV_STATE_OFFLINE;
   1078 	else
   1079 		vd->vdev_state = VDEV_STATE_CLOSED;
   1080 	vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
   1081 }
   1082 
   1083 void
   1084 vdev_reopen(vdev_t *vd)
   1085 {
   1086 	spa_t *spa = vd->vdev_spa;
   1087 
   1088 	ASSERT(spa_config_held(spa, RW_WRITER));
   1089 
   1090 	vdev_close(vd);
   1091 	(void) vdev_open(vd);
   1092 
   1093 	/*
   1094 	 * Call vdev_validate() here to make sure we have the same device.
   1095 	 * Otherwise, a device with an invalid label could be successfully
   1096 	 * opened in response to vdev_reopen().
   1097 	 */
   1098 	(void) vdev_validate(vd);
   1099 
   1100 	/*
   1101 	 * Reassess parent vdev's health.
   1102 	 */
   1103 	vdev_propagate_state(vd);
   1104 }
   1105 
   1106 int
   1107 vdev_create(vdev_t *vd, uint64_t txg, boolean_t isreplacing)
   1108 {
   1109 	int error;
   1110 
   1111 	/*
   1112 	 * Normally, partial opens (e.g. of a mirror) are allowed.
   1113 	 * For a create, however, we want to fail the request if
   1114 	 * there are any components we can't open.
   1115 	 */
   1116 	error = vdev_open(vd);
   1117 
   1118 	if (error || vd->vdev_state != VDEV_STATE_HEALTHY) {
   1119 		vdev_close(vd);
   1120 		return (error ? error : ENXIO);
   1121 	}
   1122 
   1123 	/*
   1124 	 * Recursively initialize all labels.
   1125 	 */
   1126 	if ((error = vdev_label_init(vd, txg, isreplacing ?
   1127 	    VDEV_LABEL_REPLACE : VDEV_LABEL_CREATE)) != 0) {
   1128 		vdev_close(vd);
   1129 		return (error);
   1130 	}
   1131 
   1132 	return (0);
   1133 }
   1134 
   1135 /*
   1136  * The is the latter half of vdev_create().  It is distinct because it
   1137  * involves initiating transactions in order to do metaslab creation.
   1138  * For creation, we want to try to create all vdevs at once and then undo it
   1139  * if anything fails; this is much harder if we have pending transactions.
   1140  */
   1141 void
   1142 vdev_init(vdev_t *vd, uint64_t txg)
   1143 {
   1144 	/*
   1145 	 * Aim for roughly 200 metaslabs per vdev.
   1146 	 */
   1147 	vd->vdev_ms_shift = highbit(vd->vdev_asize / 200);
   1148 	vd->vdev_ms_shift = MAX(vd->vdev_ms_shift, SPA_MAXBLOCKSHIFT);
   1149 
   1150 	/*
   1151 	 * Initialize the vdev's metaslabs.  This can't fail because
   1152 	 * there's nothing to read when creating all new metaslabs.
   1153 	 */
   1154 	VERIFY(vdev_metaslab_init(vd, txg) == 0);
   1155 }
   1156 
   1157 void
   1158 vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg)
   1159 {
   1160 	ASSERT(vd == vd->vdev_top);
   1161 	ASSERT(ISP2(flags));
   1162 
   1163 	if (flags & VDD_METASLAB)
   1164 		(void) txg_list_add(&vd->vdev_ms_list, arg, txg);
   1165 
   1166 	if (flags & VDD_DTL)
   1167 		(void) txg_list_add(&vd->vdev_dtl_list, arg, txg);
   1168 
   1169 	(void) txg_list_add(&vd->vdev_spa->spa_vdev_txg_list, vd, txg);
   1170 }
   1171 
   1172 void
   1173 vdev_dtl_dirty(space_map_t *sm, uint64_t txg, uint64_t size)
   1174 {
   1175 	mutex_enter(sm->sm_lock);
   1176 	if (!space_map_contains(sm, txg, size))
   1177 		space_map_add(sm, txg, size);
   1178 	mutex_exit(sm->sm_lock);
   1179 }
   1180 
   1181 int
   1182 vdev_dtl_contains(space_map_t *sm, uint64_t txg, uint64_t size)
   1183 {
   1184 	int dirty;
   1185 
   1186 	/*
   1187 	 * Quick test without the lock -- covers the common case that
   1188 	 * there are no dirty time segments.
   1189 	 */
   1190 	if (sm->sm_space == 0)
   1191 		return (0);
   1192 
   1193 	mutex_enter(sm->sm_lock);
   1194 	dirty = space_map_contains(sm, txg, size);
   1195 	mutex_exit(sm->sm_lock);
   1196 
   1197 	return (dirty);
   1198 }
   1199 
   1200 /*
   1201  * Reassess DTLs after a config change or scrub completion.
   1202  */
   1203 void
   1204 vdev_dtl_reassess(vdev_t *vd, uint64_t txg, uint64_t scrub_txg, int scrub_done)
   1205 {
   1206 	spa_t *spa = vd->vdev_spa;
   1207 	int c;
   1208 
   1209 	ASSERT(spa_config_held(spa, RW_WRITER));
   1210 
   1211 	if (vd->vdev_children == 0) {
   1212 		mutex_enter(&vd->vdev_dtl_lock);
   1213 		/*
   1214 		 * We're successfully scrubbed everything up to scrub_txg.
   1215 		 * Therefore, excise all old DTLs up to that point, then
   1216 		 * fold in the DTLs for everything we couldn't scrub.
   1217 		 */
   1218 		if (scrub_txg != 0) {
   1219 			space_map_excise(&vd->vdev_dtl_map, 0, scrub_txg);
   1220 			space_map_union(&vd->vdev_dtl_map, &vd->vdev_dtl_scrub);
   1221 		}
   1222 		if (scrub_done)
   1223 			space_map_vacate(&vd->vdev_dtl_scrub, NULL, NULL);
   1224 		mutex_exit(&vd->vdev_dtl_lock);
   1225 		if (txg != 0)
   1226 			vdev_dirty(vd->vdev_top, VDD_DTL, vd, txg);
   1227 		return;
   1228 	}
   1229 
   1230 	/*
   1231 	 * Make sure the DTLs are always correct under the scrub lock.
   1232 	 */
   1233 	if (vd == spa->spa_root_vdev)
   1234 		mutex_enter(&spa->spa_scrub_lock);
   1235 
   1236 	mutex_enter(&vd->vdev_dtl_lock);
   1237 	space_map_vacate(&vd->vdev_dtl_map, NULL, NULL);
   1238 	space_map_vacate(&vd->vdev_dtl_scrub, NULL, NULL);
   1239 	mutex_exit(&vd->vdev_dtl_lock);
   1240 
   1241 	for (c = 0; c < vd->vdev_children; c++) {
   1242 		vdev_t *cvd = vd->vdev_child[c];
   1243 		vdev_dtl_reassess(cvd, txg, scrub_txg, scrub_done);
   1244 		mutex_enter(&vd->vdev_dtl_lock);
   1245 		space_map_union(&vd->vdev_dtl_map, &cvd->vdev_dtl_map);
   1246 		space_map_union(&vd->vdev_dtl_scrub, &cvd->vdev_dtl_scrub);
   1247 		mutex_exit(&vd->vdev_dtl_lock);
   1248 	}
   1249 
   1250 	if (vd == spa->spa_root_vdev)
   1251 		mutex_exit(&spa->spa_scrub_lock);
   1252 }
   1253 
   1254 static int
   1255 vdev_dtl_load(vdev_t *vd)
   1256 {
   1257 	spa_t *spa = vd->vdev_spa;
   1258 	space_map_obj_t *smo = &vd->vdev_dtl;
   1259 	objset_t *mos = spa->spa_meta_objset;
   1260 	dmu_buf_t *db;
   1261 	int error;
   1262 
   1263 	ASSERT(vd->vdev_children == 0);
   1264 
   1265 	if (smo->smo_object == 0)
   1266 		return (0);
   1267 
   1268 	if ((error = dmu_bonus_hold(mos, smo->smo_object, FTAG, &db)) != 0)
   1269 		return (error);
   1270 
   1271 	ASSERT3U(db->db_size, >=, sizeof (*smo));
   1272 	bcopy(db->db_data, smo, sizeof (*smo));
   1273 	dmu_buf_rele(db, FTAG);
   1274 
   1275 	mutex_enter(&vd->vdev_dtl_lock);
   1276 	error = space_map_load(&vd->vdev_dtl_map, NULL, SM_ALLOC, smo, mos);
   1277 	mutex_exit(&vd->vdev_dtl_lock);
   1278 
   1279 	return (error);
   1280 }
   1281 
   1282 void
   1283 vdev_dtl_sync(vdev_t *vd, uint64_t txg)
   1284 {
   1285 	spa_t *spa = vd->vdev_spa;
   1286 	space_map_obj_t *smo = &vd->vdev_dtl;
   1287 	space_map_t *sm = &vd->vdev_dtl_map;
   1288 	objset_t *mos = spa->spa_meta_objset;
   1289 	space_map_t smsync;
   1290 	kmutex_t smlock;
   1291 	dmu_buf_t *db;
   1292 	dmu_tx_t *tx;
   1293 
   1294 	dprintf("%s in txg %llu pass %d\n",
   1295 	    vdev_description(vd), (u_longlong_t)txg, spa_sync_pass(spa));
   1296 
   1297 	tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
   1298 
   1299 	if (vd->vdev_detached) {
   1300 		if (smo->smo_object != 0) {
   1301 			int err = dmu_object_free(mos, smo->smo_object, tx);
   1302 			ASSERT3U(err, ==, 0);
   1303 			smo->smo_object = 0;
   1304 		}
   1305 		dmu_tx_commit(tx);
   1306 		dprintf("detach %s committed in txg %llu\n",
   1307 		    vdev_description(vd), txg);
   1308 		return;
   1309 	}
   1310 
   1311 	if (smo->smo_object == 0) {
   1312 		ASSERT(smo->smo_objsize == 0);
   1313 		ASSERT(smo->smo_alloc == 0);
   1314 		smo->smo_object = dmu_object_alloc(mos,
   1315 		    DMU_OT_SPACE_MAP, 1 << SPACE_MAP_BLOCKSHIFT,
   1316 		    DMU_OT_SPACE_MAP_HEADER, sizeof (*smo), tx);
   1317 		ASSERT(smo->smo_object != 0);
   1318 		vdev_config_dirty(vd->vdev_top);
   1319 	}
   1320 
   1321 	mutex_init(&smlock, NULL, MUTEX_DEFAULT, NULL);
   1322 
   1323 	space_map_create(&smsync, sm->sm_start, sm->sm_size, sm->sm_shift,
   1324 	    &smlock);
   1325 
   1326 	mutex_enter(&smlock);
   1327 
   1328 	mutex_enter(&vd->vdev_dtl_lock);
   1329 	space_map_walk(sm, space_map_add, &smsync);
   1330 	mutex_exit(&vd->vdev_dtl_lock);
   1331 
   1332 	space_map_truncate(smo, mos, tx);
   1333 	space_map_sync(&smsync, SM_ALLOC, smo, mos, tx);
   1334 
   1335 	space_map_destroy(&smsync);
   1336 
   1337 	mutex_exit(&smlock);
   1338 	mutex_destroy(&smlock);
   1339 
   1340 	VERIFY(0 == dmu_bonus_hold(mos, smo->smo_object, FTAG, &db));
   1341 	dmu_buf_will_dirty(db, tx);
   1342 	ASSERT3U(db->db_size, >=, sizeof (*smo));
   1343 	bcopy(smo, db->db_data, sizeof (*smo));
   1344 	dmu_buf_rele(db, FTAG);
   1345 
   1346 	dmu_tx_commit(tx);
   1347 }
   1348 
   1349 void
   1350 vdev_load(vdev_t *vd)
   1351 {
   1352 	int c;
   1353 
   1354 	/*
   1355 	 * Recursively load all children.
   1356 	 */
   1357 	for (c = 0; c < vd->vdev_children; c++)
   1358 		vdev_load(vd->vdev_child[c]);
   1359 
   1360 	/*
   1361 	 * If this is a top-level vdev, initialize its metaslabs.
   1362 	 */
   1363 	if (vd == vd->vdev_top &&
   1364 	    (vd->vdev_ashift == 0 || vd->vdev_asize == 0 ||
   1365 	    vdev_metaslab_init(vd, 0) != 0))
   1366 		vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
   1367 		    VDEV_AUX_CORRUPT_DATA);
   1368 
   1369 	/*
   1370 	 * If this is a leaf vdev, load its DTL.
   1371 	 */
   1372 	if (vd->vdev_ops->vdev_op_leaf && vdev_dtl_load(vd) != 0)
   1373 		vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
   1374 		    VDEV_AUX_CORRUPT_DATA);
   1375 }
   1376 
   1377 /*
   1378  * The special vdev case is used for hot spares and l2cache devices.  Its
   1379  * sole purpose it to set the vdev state for the associated vdev.  To do this,
   1380  * we make sure that we can open the underlying device, then try to read the
   1381  * label, and make sure that the label is sane and that it hasn't been
   1382  * repurposed to another pool.
   1383  */
   1384 int
   1385 vdev_validate_aux(vdev_t *vd)
   1386 {
   1387 	nvlist_t *label;
   1388 	uint64_t guid, version;
   1389 	uint64_t state;
   1390 
   1391 	if ((label = vdev_label_read_config(vd)) == NULL) {
   1392 		vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
   1393 		    VDEV_AUX_CORRUPT_DATA);
   1394 		return (-1);
   1395 	}
   1396 
   1397 	if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_VERSION, &version) != 0 ||
   1398 	    version > SPA_VERSION ||
   1399 	    nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, &guid) != 0 ||
   1400 	    guid != vd->vdev_guid ||
   1401 	    nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE, &state) != 0) {
   1402 		vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
   1403 		    VDEV_AUX_CORRUPT_DATA);
   1404 		nvlist_free(label);
   1405 		return (-1);
   1406 	}
   1407 
   1408 	/*
   1409 	 * We don't actually check the pool state here.  If it's in fact in
   1410 	 * use by another pool, we update this fact on the fly when requested.
   1411 	 */
   1412 	nvlist_free(label);
   1413 	return (0);
   1414 }
   1415 
   1416 void
   1417 vdev_sync_done(vdev_t *vd, uint64_t txg)
   1418 {
   1419 	metaslab_t *msp;
   1420 
   1421 	dprintf("%s txg %llu\n", vdev_description(vd), txg);
   1422 
   1423 	while (msp = txg_list_remove(&vd->vdev_ms_list, TXG_CLEAN(txg)))
   1424 		metaslab_sync_done(msp, txg);
   1425 }
   1426 
   1427 void
   1428 vdev_sync(vdev_t *vd, uint64_t txg)
   1429 {
   1430 	spa_t *spa = vd->vdev_spa;
   1431 	vdev_t *lvd;
   1432 	metaslab_t *msp;
   1433 	dmu_tx_t *tx;
   1434 
   1435 	dprintf("%s txg %llu pass %d\n",
   1436 	    vdev_description(vd), (u_longlong_t)txg, spa_sync_pass(spa));
   1437 
   1438 	if (vd->vdev_ms_array == 0 && vd->vdev_ms_shift != 0) {
   1439 		ASSERT(vd == vd->vdev_top);
   1440 		tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
   1441 		vd->vdev_ms_array = dmu_object_alloc(spa->spa_meta_objset,
   1442 		    DMU_OT_OBJECT_ARRAY, 0, DMU_OT_NONE, 0, tx);
   1443 		ASSERT(vd->vdev_ms_array != 0);
   1444 		vdev_config_dirty(vd);
   1445 		dmu_tx_commit(tx);
   1446 	}
   1447 
   1448 	while ((msp = txg_list_remove(&vd->vdev_ms_list, txg)) != NULL) {
   1449 		metaslab_sync(msp, txg);
   1450 		(void) txg_list_add(&vd->vdev_ms_list, msp, TXG_CLEAN(txg));
   1451 	}
   1452 
   1453 	while ((lvd = txg_list_remove(&vd->vdev_dtl_list, txg)) != NULL)
   1454 		vdev_dtl_sync(lvd, txg);
   1455 
   1456 	(void) txg_list_add(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg));
   1457 }
   1458 
   1459 uint64_t
   1460 vdev_psize_to_asize(vdev_t *vd, uint64_t psize)
   1461 {
   1462 	return (vd->vdev_ops->vdev_op_asize(vd, psize));
   1463 }
   1464 
   1465 const char *
   1466 vdev_description(vdev_t *vd)
   1467 {
   1468 	if (vd == NULL || vd->vdev_ops == NULL)
   1469 		return ("<unknown>");
   1470 
   1471 	if (vd->vdev_path != NULL)
   1472 		return (vd->vdev_path);
   1473 
   1474 	if (vd->vdev_parent == NULL)
   1475 		return (spa_name(vd->vdev_spa));
   1476 
   1477 	return (vd->vdev_ops->vdev_op_type);
   1478 }
   1479 
   1480 /*
   1481  * Mark the given vdev faulted.  A faulted vdev behaves as if the device could
   1482  * not be opened, and no I/O is attempted.
   1483  */
   1484 int
   1485 vdev_fault(spa_t *spa, uint64_t guid)
   1486 {
   1487 	vdev_t *rvd, *vd;
   1488 	uint64_t txg;
   1489 
   1490 	/*
   1491 	 * Disregard a vdev fault request if the pool has
   1492 	 * experienced a complete failure.
   1493 	 *
   1494 	 * XXX - We do this here so that we don't hold the
   1495 	 * spa_namespace_lock in the event that we can't get
   1496 	 * the RW_WRITER spa_config_lock.
   1497 	 */
   1498 	if (spa_state(spa) == POOL_STATE_IO_FAILURE)
   1499 		return (EIO);
   1500 
   1501 	txg = spa_vdev_enter(spa);
   1502 
   1503 	rvd = spa->spa_root_vdev;
   1504 
   1505 	if ((vd = vdev_lookup_by_guid(rvd, guid)) == NULL)
   1506 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
   1507 	if (!vd->vdev_ops->vdev_op_leaf)
   1508 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
   1509 
   1510 	/*
   1511 	 * Faulted state takes precedence over degraded.
   1512 	 */
   1513 	vd->vdev_faulted = 1ULL;
   1514 	vd->vdev_degraded = 0ULL;
   1515 	vdev_set_state(vd, B_FALSE, VDEV_STATE_FAULTED,
   1516 	    VDEV_AUX_ERR_EXCEEDED);
   1517 
   1518 	/*
   1519 	 * If marking the vdev as faulted cause the toplevel vdev to become
   1520 	 * unavailable, then back off and simply mark the vdev as degraded
   1521 	 * instead.
   1522 	 */
   1523 	if (vdev_is_dead(vd->vdev_top)) {
   1524 		vd->vdev_degraded = 1ULL;
   1525 		vd->vdev_faulted = 0ULL;
   1526 
   1527 		/*
   1528 		 * If we reopen the device and it's not dead, only then do we
   1529 		 * mark it degraded.
   1530 		 */
   1531 		vdev_reopen(vd);
   1532 
   1533 		if (vdev_readable(vd)) {
   1534 			vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED,
   1535 			    VDEV_AUX_ERR_EXCEEDED);
   1536 		}
   1537 	}
   1538 
   1539 	vdev_config_dirty(vd->vdev_top);
   1540 
   1541 	(void) spa_vdev_exit(spa, NULL, txg, 0);
   1542 
   1543 	return (0);
   1544 }
   1545 
   1546 /*
   1547  * Mark the given vdev degraded.  A degraded vdev is purely an indication to the
   1548  * user that something is wrong.  The vdev continues to operate as normal as far
   1549  * as I/O is concerned.
   1550  */
   1551 int
   1552 vdev_degrade(spa_t *spa, uint64_t guid)
   1553 {
   1554 	vdev_t *rvd, *vd;
   1555 	uint64_t txg;
   1556 
   1557 	/*
   1558 	 * Disregard a vdev fault request if the pool has
   1559 	 * experienced a complete failure.
   1560 	 *
   1561 	 * XXX - We do this here so that we don't hold the
   1562 	 * spa_namespace_lock in the event that we can't get
   1563 	 * the RW_WRITER spa_config_lock.
   1564 	 */
   1565 	if (spa_state(spa) == POOL_STATE_IO_FAILURE)
   1566 		return (EIO);
   1567 
   1568 	txg = spa_vdev_enter(spa);
   1569 
   1570 	rvd = spa->spa_root_vdev;
   1571 
   1572 	if ((vd = vdev_lookup_by_guid(rvd, guid)) == NULL)
   1573 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
   1574 	if (!vd->vdev_ops->vdev_op_leaf)
   1575 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
   1576 
   1577 	/*
   1578 	 * If the vdev is already faulted, then don't do anything.
   1579 	 */
   1580 	if (vd->vdev_faulted || vd->vdev_degraded) {
   1581 		(void) spa_vdev_exit(spa, NULL, txg, 0);
   1582 		return (0);
   1583 	}
   1584 
   1585 	vd->vdev_degraded = 1ULL;
   1586 	if (!vdev_is_dead(vd))
   1587 		vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED,
   1588 		    VDEV_AUX_ERR_EXCEEDED);
   1589 	vdev_config_dirty(vd->vdev_top);
   1590 
   1591 	(void) spa_vdev_exit(spa, NULL, txg, 0);
   1592 
   1593 	return (0);
   1594 }
   1595 
   1596 /*
   1597  * Online the given vdev.  If 'unspare' is set, it implies two things.  First,
   1598  * any attached spare device should be detached when the device finishes
   1599  * resilvering.  Second, the online should be treated like a 'test' online case,
   1600  * so no FMA events are generated if the device fails to open.
   1601  */
   1602 int
   1603 vdev_online(spa_t *spa, uint64_t guid, uint64_t flags,
   1604     vdev_state_t *newstate)
   1605 {
   1606 	vdev_t *rvd, *vd;
   1607 	uint64_t txg;
   1608 
   1609 	/*
   1610 	 * Disregard a vdev fault request if the pool has
   1611 	 * experienced a complete failure.
   1612 	 *
   1613 	 * XXX - We do this here so that we don't hold the
   1614 	 * spa_namespace_lock in the event that we can't get
   1615 	 * the RW_WRITER spa_config_lock.
   1616 	 */
   1617 	if (spa_state(spa) == POOL_STATE_IO_FAILURE)
   1618 		return (EIO);
   1619 
   1620 	txg = spa_vdev_enter(spa);
   1621 
   1622 	rvd = spa->spa_root_vdev;
   1623 
   1624 	if ((vd = vdev_lookup_by_guid(rvd, guid)) == NULL)
   1625 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
   1626 
   1627 	if (!vd->vdev_ops->vdev_op_leaf)
   1628 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
   1629 
   1630 	vd->vdev_offline = B_FALSE;
   1631 	vd->vdev_tmpoffline = B_FALSE;
   1632 	vd->vdev_checkremove = (flags & ZFS_ONLINE_CHECKREMOVE) ?
   1633 	    B_TRUE : B_FALSE;
   1634 	vd->vdev_forcefault = (flags & ZFS_ONLINE_FORCEFAULT) ?
   1635 	    B_TRUE : B_FALSE;
   1636 	vdev_reopen(vd->vdev_top);
   1637 	vd->vdev_checkremove = vd->vdev_forcefault = B_FALSE;
   1638 
   1639 	if (newstate)
   1640 		*newstate = vd->vdev_state;
   1641 	if ((flags & ZFS_ONLINE_UNSPARE) &&
   1642 	    !vdev_is_dead(vd) && vd->vdev_parent &&
   1643 	    vd->vdev_parent->vdev_ops == &vdev_spare_ops &&
   1644 	    vd->vdev_parent->vdev_child[0] == vd)
   1645 		vd->vdev_unspare = B_TRUE;
   1646 
   1647 	vdev_config_dirty(vd->vdev_top);
   1648 
   1649 	(void) spa_vdev_exit(spa, NULL, txg, 0);
   1650 
   1651 	/*
   1652 	 * Must hold spa_namespace_lock in order to post resilver sysevent
   1653 	 * w/pool name.
   1654 	 */
   1655 	mutex_enter(&spa_namespace_lock);
   1656 	VERIFY(spa_scrub(spa, POOL_SCRUB_RESILVER, B_TRUE) == 0);
   1657 	mutex_exit(&spa_namespace_lock);
   1658 
   1659 	return (0);
   1660 }
   1661 
   1662 int
   1663 vdev_offline(spa_t *spa, uint64_t guid, uint64_t flags)
   1664 {
   1665 	vdev_t *rvd, *vd;
   1666 	uint64_t txg;
   1667 
   1668 	/*
   1669 	 * Disregard a vdev fault request if the pool has
   1670 	 * experienced a complete failure.
   1671 	 *
   1672 	 * XXX - We do this here so that we don't hold the
   1673 	 * spa_namespace_lock in the event that we can't get
   1674 	 * the RW_WRITER spa_config_lock.
   1675 	 */
   1676 	if (spa_state(spa) == POOL_STATE_IO_FAILURE)
   1677 		return (EIO);
   1678 
   1679 	txg = spa_vdev_enter(spa);
   1680 
   1681 	rvd = spa->spa_root_vdev;
   1682 
   1683 	if ((vd = vdev_lookup_by_guid(rvd, guid)) == NULL)
   1684 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
   1685 
   1686 	if (!vd->vdev_ops->vdev_op_leaf)
   1687 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
   1688 
   1689 	/*
   1690 	 * If the device isn't already offline, try to offline it.
   1691 	 */
   1692 	if (!vd->vdev_offline) {
   1693 		/*
   1694 		 * If this device's top-level vdev has a non-empty DTL,
   1695 		 * don't allow the device to be offlined.
   1696 		 *
   1697 		 * XXX -- make this more precise by allowing the offline
   1698 		 * as long as the remaining devices don't have any DTL holes.
   1699 		 */
   1700 		if (vd->vdev_top->vdev_dtl_map.sm_space != 0)
   1701 			return (spa_vdev_exit(spa, NULL, txg, EBUSY));
   1702 
   1703 		/*
   1704 		 * Offline this device and reopen its top-level vdev.
   1705 		 * If this action results in the top-level vdev becoming
   1706 		 * unusable, undo it and fail the request.
   1707 		 */
   1708 		vd->vdev_offline = B_TRUE;
   1709 		vdev_reopen(vd->vdev_top);
   1710 		if (vdev_is_dead(vd->vdev_top)) {
   1711 			vd->vdev_offline = B_FALSE;
   1712 			vdev_reopen(vd->vdev_top);
   1713 			return (spa_vdev_exit(spa, NULL, txg, EBUSY));
   1714 		}
   1715 	}
   1716 
   1717 	vd->vdev_tmpoffline = (flags & ZFS_OFFLINE_TEMPORARY) ?
   1718 	    B_TRUE : B_FALSE;
   1719 
   1720 	vdev_config_dirty(vd->vdev_top);
   1721 
   1722 	return (spa_vdev_exit(spa, NULL, txg, 0));
   1723 }
   1724 
   1725 /*
   1726  * Clear the error counts associated with this vdev.  Unlike vdev_online() and
   1727  * vdev_offline(), we assume the spa config is locked.  We also clear all
   1728  * children.  If 'vd' is NULL, then the user wants to clear all vdevs.
   1729  * If reopen is specified then attempt to reopen the vdev if the vdev is
   1730  * faulted or degraded.
   1731  */
   1732 void
   1733 vdev_clear(spa_t *spa, vdev_t *vd, boolean_t reopen_wanted)
   1734 {
   1735 	int c;
   1736 
   1737 	if (vd == NULL)
   1738 		vd = spa->spa_root_vdev;
   1739 
   1740 	vd->vdev_stat.vs_read_errors = 0;
   1741 	vd->vdev_stat.vs_write_errors = 0;
   1742 	vd->vdev_stat.vs_checksum_errors = 0;
   1743 	vd->vdev_is_failing = B_FALSE;
   1744 
   1745 	for (c = 0; c < vd->vdev_children; c++)
   1746 		vdev_clear(spa, vd->vdev_child[c], reopen_wanted);
   1747 
   1748 	/*
   1749 	 * If we're in the FAULTED state, then clear the persistent state and
   1750 	 * attempt to reopen the device.  We also mark the vdev config dirty, so
   1751 	 * that the new faulted state is written out to disk.
   1752 	 */
   1753 	if (reopen_wanted && (vd->vdev_faulted || vd->vdev_degraded)) {
   1754 		vd->vdev_faulted = vd->vdev_degraded = 0;
   1755 		vdev_reopen(vd);
   1756 		vdev_config_dirty(vd->vdev_top);
   1757 
   1758 		if (vd->vdev_faulted)
   1759 			spa_async_request(spa, SPA_ASYNC_RESILVER);
   1760 
   1761 		spa_event_notify(spa, vd, ESC_ZFS_VDEV_CLEAR);
   1762 	}
   1763 }
   1764 
   1765 int
   1766 vdev_readable(vdev_t *vd)
   1767 {
   1768 	/* XXPOLICY */
   1769 	return (!vdev_is_dead(vd));
   1770 }
   1771 
   1772 int
   1773 vdev_writeable(vdev_t *vd)
   1774 {
   1775 	return (!vdev_is_dead(vd) && !vd->vdev_is_failing);
   1776 }
   1777 
   1778 int
   1779 vdev_is_dead(vdev_t *vd)
   1780 {
   1781 	return (vd->vdev_state < VDEV_STATE_DEGRADED);
   1782 }
   1783 
   1784 int
   1785 vdev_error_inject(vdev_t *vd, zio_t *zio)
   1786 {
   1787 	int error = 0;
   1788 
   1789 	if (vd->vdev_fault_mode == VDEV_FAULT_NONE)
   1790 		return (0);
   1791 
   1792 	if (((1ULL << zio->io_type) & vd->vdev_fault_mask) == 0)
   1793 		return (0);
   1794 
   1795 	switch (vd->vdev_fault_mode) {
   1796 	case VDEV_FAULT_RANDOM:
   1797 		if (spa_get_random(vd->vdev_fault_arg) == 0)
   1798 			error = EIO;
   1799 		break;
   1800 
   1801 	case VDEV_FAULT_COUNT:
   1802 		if ((int64_t)--vd->vdev_fault_arg <= 0)
   1803 			vd->vdev_fault_mode = VDEV_FAULT_NONE;
   1804 		error = EIO;
   1805 		break;
   1806 	}
   1807 
   1808 	return (error);
   1809 }
   1810 
   1811 /*
   1812  * Get statistics for the given vdev.
   1813  */
   1814 void
   1815 vdev_get_stats(vdev_t *vd, vdev_stat_t *vs)
   1816 {
   1817 	vdev_t *rvd = vd->vdev_spa->spa_root_vdev;
   1818 	int c, t;
   1819 
   1820 	mutex_enter(&vd->vdev_stat_lock);
   1821 	bcopy(&vd->vdev_stat, vs, sizeof (*vs));
   1822 	vs->vs_timestamp = gethrtime() - vs->vs_timestamp;
   1823 	vs->vs_state = vd->vdev_state;
   1824 	vs->vs_rsize = vdev_get_rsize(vd);
   1825 	mutex_exit(&vd->vdev_stat_lock);
   1826 
   1827 	/*
   1828 	 * If we're getting stats on the root vdev, aggregate the I/O counts
   1829 	 * over all top-level vdevs (i.e. the direct children of the root).
   1830 	 */
   1831 	if (vd == rvd) {
   1832 		for (c = 0; c < rvd->vdev_children; c++) {
   1833 			vdev_t *cvd = rvd->vdev_child[c];
   1834 			vdev_stat_t *cvs = &cvd->vdev_stat;
   1835 
   1836 			mutex_enter(&vd->vdev_stat_lock);
   1837 			for (t = 0; t < ZIO_TYPES; t++) {
   1838 				vs->vs_ops[t] += cvs->vs_ops[t];
   1839 				vs->vs_bytes[t] += cvs->vs_bytes[t];
   1840 			}
   1841 			vs->vs_read_errors += cvs->vs_read_errors;
   1842 			vs->vs_write_errors += cvs->vs_write_errors;
   1843 			vs->vs_checksum_errors += cvs->vs_checksum_errors;
   1844 			vs->vs_scrub_examined += cvs->vs_scrub_examined;
   1845 			vs->vs_scrub_errors += cvs->vs_scrub_errors;
   1846 			mutex_exit(&vd->vdev_stat_lock);
   1847 		}
   1848 	}
   1849 }
   1850 
   1851 void
   1852 vdev_clear_stats(vdev_t *vd)
   1853 {
   1854 	mutex_enter(&vd->vdev_stat_lock);
   1855 	vd->vdev_stat.vs_space = 0;
   1856 	vd->vdev_stat.vs_dspace = 0;
   1857 	vd->vdev_stat.vs_alloc = 0;
   1858 	mutex_exit(&vd->vdev_stat_lock);
   1859 }
   1860 
   1861 void
   1862 vdev_stat_update(zio_t *zio)
   1863 {
   1864 	vdev_t *vd = zio->io_vd;
   1865 	vdev_t *pvd;
   1866 	uint64_t txg = zio->io_txg;
   1867 	vdev_stat_t *vs = &vd->vdev_stat;
   1868 	zio_type_t type = zio->io_type;
   1869 	int flags = zio->io_flags;
   1870 
   1871 	if (zio->io_error == 0) {
   1872 		if (!(flags & ZIO_FLAG_IO_BYPASS)) {
   1873 			mutex_enter(&vd->vdev_stat_lock);
   1874 			vs->vs_ops[type]++;
   1875 			vs->vs_bytes[type] += zio->io_size;
   1876 			mutex_exit(&vd->vdev_stat_lock);
   1877 		}
   1878 		if ((flags & ZIO_FLAG_IO_REPAIR) &&
   1879 		    zio->io_delegate_list == NULL) {
   1880 			mutex_enter(&vd->vdev_stat_lock);
   1881 			if (flags & ZIO_FLAG_SCRUB_THREAD)
   1882 				vs->vs_scrub_repaired += zio->io_size;
   1883 			else
   1884 				vs->vs_self_healed += zio->io_size;
   1885 			mutex_exit(&vd->vdev_stat_lock);
   1886 		}
   1887 		return;
   1888 	}
   1889 
   1890 	if (flags & ZIO_FLAG_SPECULATIVE)
   1891 		return;
   1892 
   1893 	if (vdev_readable(vd)) {
   1894 		mutex_enter(&vd->vdev_stat_lock);
   1895 		if (type == ZIO_TYPE_READ) {
   1896 			if (zio->io_error == ECKSUM)
   1897 				vs->vs_checksum_errors++;
   1898 			else
   1899 				vs->vs_read_errors++;
   1900 		}
   1901 		if (type == ZIO_TYPE_WRITE)
   1902 			vs->vs_write_errors++;
   1903 		mutex_exit(&vd->vdev_stat_lock);
   1904 	}
   1905 
   1906 	if (type == ZIO_TYPE_WRITE) {
   1907 		if (txg == 0 || vd->vdev_children != 0)
   1908 			return;
   1909 		if (flags & ZIO_FLAG_SCRUB_THREAD) {
   1910 			ASSERT(flags & ZIO_FLAG_IO_REPAIR);
   1911 			for (pvd = vd; pvd != NULL; pvd = pvd->vdev_parent)
   1912 				vdev_dtl_dirty(&pvd->vdev_dtl_scrub, txg, 1);
   1913 		}
   1914 		if (!(flags & ZIO_FLAG_IO_REPAIR)) {
   1915 			if (vdev_dtl_contains(&vd->vdev_dtl_map, txg, 1))
   1916 				return;
   1917 			vdev_dirty(vd->vdev_top, VDD_DTL, vd, txg);
   1918 			for (pvd = vd; pvd != NULL; pvd = pvd->vdev_parent)
   1919 				vdev_dtl_dirty(&pvd->vdev_dtl_map, txg, 1);
   1920 		}
   1921 	}
   1922 }
   1923 
   1924 void
   1925 vdev_scrub_stat_update(vdev_t *vd, pool_scrub_type_t type, boolean_t complete)
   1926 {
   1927 	int c;
   1928 	vdev_stat_t *vs = &vd->vdev_stat;
   1929 
   1930 	for (c = 0; c < vd->vdev_children; c++)
   1931 		vdev_scrub_stat_update(vd->vdev_child[c], type, complete);
   1932 
   1933 	mutex_enter(&vd->vdev_stat_lock);
   1934 
   1935 	if (type == POOL_SCRUB_NONE) {
   1936 		/*
   1937 		 * Update completion and end time.  Leave everything else alone
   1938 		 * so we can report what happened during the previous scrub.
   1939 		 */
   1940 		vs->vs_scrub_complete = complete;
   1941 		vs->vs_scrub_end = gethrestime_sec();
   1942 	} else {
   1943 		vs->vs_scrub_type = type;
   1944 		vs->vs_scrub_complete = 0;
   1945 		vs->vs_scrub_examined = 0;
   1946 		vs->vs_scrub_repaired = 0;
   1947 		vs->vs_scrub_errors = 0;
   1948 		vs->vs_scrub_start = gethrestime_sec();
   1949 		vs->vs_scrub_end = 0;
   1950 	}
   1951 
   1952 	mutex_exit(&vd->vdev_stat_lock);
   1953 }
   1954 
   1955 /*
   1956  * Update the in-core space usage stats for this vdev and the root vdev.
   1957  */
   1958 void
   1959 vdev_space_update(vdev_t *vd, int64_t space_delta, int64_t alloc_delta,
   1960     boolean_t update_root)
   1961 {
   1962 	int64_t dspace_delta = space_delta;
   1963 	spa_t *spa = vd->vdev_spa;
   1964 	vdev_t *rvd = spa->spa_root_vdev;
   1965 
   1966 	ASSERT(vd == vd->vdev_top);
   1967 
   1968 	/*
   1969 	 * Apply the inverse of the psize-to-asize (ie. RAID-Z) space-expansion
   1970 	 * factor.  We must calculate this here and not at the root vdev
   1971 	 * because the root vdev's psize-to-asize is simply the max of its
   1972 	 * childrens', thus not accurate enough for us.
   1973 	 */
   1974 	ASSERT((dspace_delta & (SPA_MINBLOCKSIZE-1)) == 0);
   1975 	dspace_delta = (dspace_delta >> SPA_MINBLOCKSHIFT) *
   1976 	    vd->vdev_deflate_ratio;
   1977 
   1978 	mutex_enter(&vd->vdev_stat_lock);
   1979 	vd->vdev_stat.vs_space += space_delta;
   1980 	vd->vdev_stat.vs_alloc += alloc_delta;
   1981 	vd->vdev_stat.vs_dspace += dspace_delta;
   1982 	mutex_exit(&vd->vdev_stat_lock);
   1983 
   1984 	if (update_root) {
   1985 		ASSERT(rvd == vd->vdev_parent);
   1986 		ASSERT(vd->vdev_ms_count != 0);
   1987 
   1988 		/*
   1989 		 * Don't count non-normal (e.g. intent log) space as part of
   1990 		 * the pool's capacity.
   1991 		 */
   1992 		if (vd->vdev_mg->mg_class != spa->spa_normal_class)
   1993 			return;
   1994 
   1995 		mutex_enter(&rvd->vdev_stat_lock);
   1996 		rvd->vdev_stat.vs_space += space_delta;
   1997 		rvd->vdev_stat.vs_alloc += alloc_delta;
   1998 		rvd->vdev_stat.vs_dspace += dspace_delta;
   1999 		mutex_exit(&rvd->vdev_stat_lock);
   2000 	}
   2001 }
   2002 
   2003 /*
   2004  * Mark a top-level vdev's config as dirty, placing it on the dirty list
   2005  * so that it will be written out next time the vdev configuration is synced.
   2006  * If the root vdev is specified (vdev_top == NULL), dirty all top-level vdevs.
   2007  */
   2008 void
   2009 vdev_config_dirty(vdev_t *vd)
   2010 {
   2011 	spa_t *spa = vd->vdev_spa;
   2012 	vdev_t *rvd = spa->spa_root_vdev;
   2013 	int c;
   2014 
   2015 	/*
   2016 	 * The dirty list is protected by the config lock.  The caller must
   2017 	 * either hold the config lock as writer, or must be the sync thread
   2018 	 * (which holds the lock as reader).  There's only one sync thread,
   2019 	 * so this is sufficient to ensure mutual exclusion.
   2020 	 */
   2021 	ASSERT(spa_config_held(spa, RW_WRITER) ||
   2022 	    dsl_pool_sync_context(spa_get_dsl(spa)));
   2023 
   2024 	if (vd == rvd) {
   2025 		for (c = 0; c < rvd->vdev_children; c++)
   2026 			vdev_config_dirty(rvd->vdev_child[c]);
   2027 	} else {
   2028 		ASSERT(vd == vd->vdev_top);
   2029 
   2030 		if (!list_link_active(&vd->vdev_dirty_node))
   2031 			list_insert_head(&spa->spa_dirty_list, vd);
   2032 	}
   2033 }
   2034 
   2035 void
   2036 vdev_config_clean(vdev_t *vd)
   2037 {
   2038 	spa_t *spa = vd->vdev_spa;
   2039 
   2040 	ASSERT(spa_config_held(spa, RW_WRITER) ||
   2041 	    dsl_pool_sync_context(spa_get_dsl(spa)));
   2042 
   2043 	ASSERT(list_link_active(&vd->vdev_dirty_node));
   2044 	list_remove(&spa->spa_dirty_list, vd);
   2045 }
   2046 
   2047 void
   2048 vdev_propagate_state(vdev_t *vd)
   2049 {
   2050 	vdev_t *rvd = vd->vdev_spa->spa_root_vdev;
   2051 	int degraded = 0, faulted = 0;
   2052 	int corrupted = 0;
   2053 	int c;
   2054 	vdev_t *child;
   2055 
   2056 	if (vd->vdev_children > 0) {
   2057 		for (c = 0; c < vd->vdev_children; c++) {
   2058 			child = vd->vdev_child[c];
   2059 			if (vdev_is_dead(child) && !vdev_readable(child))
   2060 				faulted++;
   2061 			else if (child->vdev_state <= VDEV_STATE_DEGRADED)
   2062 				degraded++;
   2063 
   2064 			if (child->vdev_stat.vs_aux == VDEV_AUX_CORRUPT_DATA)
   2065 				corrupted++;
   2066 		}
   2067 
   2068 		vd->vdev_ops->vdev_op_state_change(vd, faulted, degraded);
   2069 
   2070 		/*
   2071 		 * Root special: if there is a toplevel vdev that cannot be
   2072 		 * opened due to corrupted metadata, then propagate the root
   2073 		 * vdev's aux state as 'corrupt' rather than 'insufficient
   2074 		 * replicas'.
   2075 		 */
   2076 		if (corrupted && vd == rvd &&
   2077 		    rvd->vdev_state == VDEV_STATE_CANT_OPEN)
   2078 			vdev_set_state(rvd, B_FALSE, VDEV_STATE_CANT_OPEN,
   2079 			    VDEV_AUX_CORRUPT_DATA);
   2080 	}
   2081 
   2082 	if (vd->vdev_parent && !vd->vdev_islog)
   2083 		vdev_propagate_state(vd->vdev_parent);
   2084 }
   2085 
   2086 /*
   2087  * Set a vdev's state.  If this is during an open, we don't update the parent
   2088  * state, because we're in the process of opening children depth-first.
   2089  * Otherwise, we propagate the change to the parent.
   2090  *
   2091  * If this routine places a device in a faulted state, an appropriate ereport is
   2092  * generated.
   2093  */
   2094 void
   2095 vdev_set_state(vdev_t *vd, boolean_t isopen, vdev_state_t state, vdev_aux_t aux)
   2096 {
   2097 	uint64_t save_state;
   2098 
   2099 	if (state == vd->vdev_state) {
   2100 		vd->vdev_stat.vs_aux = aux;
   2101 		return;
   2102 	}
   2103 
   2104 	save_state = vd->vdev_state;
   2105 
   2106 	vd->vdev_state = state;
   2107 	vd->vdev_stat.vs_aux = aux;
   2108 
   2109 	/*
   2110 	 * If we are setting the vdev state to anything but an open state, then
   2111 	 * always close the underlying device.  Otherwise, we keep accessible
   2112 	 * but invalid devices open forever.  We don't call vdev_close() itself,
   2113 	 * because that implies some extra checks (offline, etc) that we don't
   2114 	 * want here.  This is limited to leaf devices, because otherwise
   2115 	 * closing the device will affect other children.
   2116 	 */
   2117 	if (!vdev_readable(vd) && vd->vdev_ops->vdev_op_leaf)
   2118 		vd->vdev_ops->vdev_op_close(vd);
   2119 
   2120 	if (vd->vdev_removed &&
   2121 	    state == VDEV_STATE_CANT_OPEN &&
   2122 	    (aux == VDEV_AUX_OPEN_FAILED || vd->vdev_checkremove)) {
   2123 		/*
   2124 		 * If the previous state is set to VDEV_STATE_REMOVED, then this
   2125 		 * device was previously marked removed and someone attempted to
   2126 		 * reopen it.  If this failed due to a nonexistent device, then
   2127 		 * keep the device in the REMOVED state.  We also let this be if
   2128 		 * it is one of our special test online cases, which is only
   2129 		 * attempting to online the device and shouldn't generate an FMA
   2130 		 * fault.
   2131 		 */
   2132 		vd->vdev_state = VDEV_STATE_REMOVED;
   2133 		vd->vdev_stat.vs_aux = VDEV_AUX_NONE;
   2134 	} else if (state == VDEV_STATE_REMOVED) {
   2135 		/*
   2136 		 * Indicate to the ZFS DE that this device has been removed, and
   2137 		 * any recent errors should be ignored.
   2138 		 */
   2139 		zfs_post_remove(vd->vdev_spa, vd);
   2140 		vd->vdev_removed = B_TRUE;
   2141 	} else if (state == VDEV_STATE_CANT_OPEN) {
   2142 		/*
   2143 		 * If we fail to open a vdev during an import, we mark it as
   2144 		 * "not available", which signifies that it was never there to
   2145 		 * begin with.  Failure to open such a device is not considered
   2146 		 * an error.
   2147 		 */
   2148 		if (vd->vdev_spa->spa_load_state == SPA_LOAD_IMPORT &&
   2149 		    vd->vdev_ops->vdev_op_leaf)
   2150 			vd->vdev_not_present = 1;
   2151 
   2152 		/*
   2153 		 * Post the appropriate ereport.  If the 'prevstate' field is
   2154 		 * set to something other than VDEV_STATE_UNKNOWN, it indicates
   2155 		 * that this is part of a vdev_reopen().  In this case, we don't
   2156 		 * want to post the ereport if the device was already in the
   2157 		 * CANT_OPEN state beforehand.
   2158 		 *
   2159 		 * If the 'checkremove' flag is set, then this is an attempt to
   2160 		 * online the device in response to an insertion event.  If we
   2161 		 * hit this case, then we have detected an insertion event for a
   2162 		 * faulted or offline device that wasn't in the removed state.
   2163 		 * In this scenario, we don't post an ereport because we are
   2164 		 * about to replace the device, or attempt an online with
   2165 		 * vdev_forcefault, which will generate the fault for us.
   2166 		 */
   2167 		if ((vd->vdev_prevstate != state || vd->vdev_forcefault) &&
   2168 		    !vd->vdev_not_present && !vd->vdev_checkremove &&
   2169 		    vd != vd->vdev_spa->spa_root_vdev) {
   2170 			const char *class;
   2171 
   2172 			switch (aux) {
   2173 			case VDEV_AUX_OPEN_FAILED:
   2174 				class = FM_EREPORT_ZFS_DEVICE_OPEN_FAILED;
   2175 				break;
   2176 			case VDEV_AUX_CORRUPT_DATA:
   2177 				class = FM_EREPORT_ZFS_DEVICE_CORRUPT_DATA;
   2178 				break;
   2179 			case VDEV_AUX_NO_REPLICAS:
   2180 				class = FM_EREPORT_ZFS_DEVICE_NO_REPLICAS;
   2181 				break;
   2182 			case VDEV_AUX_BAD_GUID_SUM:
   2183 				class = FM_EREPORT_ZFS_DEVICE_BAD_GUID_SUM;
   2184 				break;
   2185 			case VDEV_AUX_TOO_SMALL:
   2186 				class = FM_EREPORT_ZFS_DEVICE_TOO_SMALL;
   2187 				break;
   2188 			case VDEV_AUX_BAD_LABEL:
   2189 				class = FM_EREPORT_ZFS_DEVICE_BAD_LABEL;
   2190 				break;
   2191 			default:
   2192 				class = FM_EREPORT_ZFS_DEVICE_UNKNOWN;
   2193 			}
   2194 
   2195 			zfs_ereport_post(class, vd->vdev_spa,
   2196 			    vd, NULL, save_state, 0);
   2197 		}
   2198 
   2199 		/* Erase any notion of persistent removed state */
   2200 		vd->vdev_removed = B_FALSE;
   2201 	} else {
   2202 		vd->vdev_removed = B_FALSE;
   2203 	}
   2204 
   2205 	if (!isopen)
   2206 		vdev_propagate_state(vd);
   2207 }
   2208