xref: /freebsd/sys/contrib/openzfs/cmd/zdb/zdb.c (revision dd32d6b29d49838c99d38ba30846ade210b2e6f7)

// SPDX-License-Identifier: CDDL-1.0
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or https://opensource.org/licenses/CDDL-1.0.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2011, 2019 by Delphix. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 * Copyright 2016 Nexenta Systems, Inc.
 * Copyright (c) 2017, 2018 Lawrence Livermore National Security, LLC.
 * Copyright (c) 2015, 2017, Intel Corporation.
 * Copyright (c) 2020 Datto Inc.
 * Copyright (c) 2020, The FreeBSD Foundation [1]
 *
 * [1] Portions of this software were developed by Allan Jude
 *     under sponsorship from the FreeBSD Foundation.
 * Copyright (c) 2021 Allan Jude
 * Copyright (c) 2021 Toomas Soome <tsoome@me.com>
 * Copyright (c) 2023, 2024, Klara Inc.
 * Copyright (c) 2023, Rob Norris <robn@despairlabs.com>
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <getopt.h>
#include <openssl/evp.h>
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/dmu.h>
#include <sys/zap.h>
#include <sys/zap_impl.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_sa.h>
#include <sys/sa.h>
#include <sys/sa_impl.h>
#include <sys/vdev.h>
#include <sys/vdev_impl.h>
#include <sys/metaslab_impl.h>
#include <sys/dmu_objset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_bookmark.h>
#include <sys/dbuf.h>
#include <sys/zil.h>
#include <sys/zil_impl.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <sys/dmu_send.h>
#include <sys/dmu_traverse.h>
#include <sys/zio_checksum.h>
#include <sys/zio_compress.h>
#include <sys/zfs_fuid.h>
#include <sys/arc.h>
#include <sys/arc_impl.h>
#include <sys/ddt.h>
#include <sys/ddt_impl.h>
#include <sys/zfeature.h>
#include <sys/abd.h>
#include <sys/blkptr.h>
#include <sys/dsl_crypt.h>
#include <sys/dsl_scan.h>
#include <sys/btree.h>
#include <sys/brt.h>
#include <sys/brt_impl.h>
#include <zfs_comutil.h>
#include <sys/zstd/zstd.h>
#include <sys/backtrace.h>

#include <libnvpair.h>
#include <libzutil.h>
#include <libzfs_core.h>

#include <libzdb.h>

#include "zdb.h"


extern int reference_tracking_enable;
extern int zfs_recover;
extern uint_t zfs_vdev_async_read_max_active;
extern boolean_t spa_load_verify_dryrun;
extern boolean_t spa_mode_readable_spacemaps;
extern uint_t zfs_reconstruct_indirect_combinations_max;
extern uint_t zfs_btree_verify_intensity;

static const char cmdname[] = "zdb";
uint8_t dump_opt[512];

#define	ALLOCATED_OPT	256

typedef void object_viewer_t(objset_t *, uint64_t, void *data, size_t size);

static uint64_t *zopt_metaslab = NULL;
static unsigned zopt_metaslab_args = 0;


static zopt_object_range_t *zopt_object_ranges = NULL;
static unsigned zopt_object_args = 0;

static int flagbits[256];


static uint64_t max_inflight_bytes = 256 * 1024 * 1024; /* 256MB */
static int leaked_objects = 0;
static zfs_range_tree_t *mos_refd_objs;
static spa_t *spa;
static objset_t *os;
static boolean_t kernel_init_done;
static boolean_t corruption_found = B_FALSE;

static void snprintf_blkptr_compact(char *, size_t, const blkptr_t *,
    boolean_t);
static void mos_obj_refd(uint64_t);
static void mos_obj_refd_multiple(uint64_t);
static int dump_bpobj_cb(void *arg, const blkptr_t *bp, boolean_t free,
    dmu_tx_t *tx);



static void zdb_print_blkptr(const blkptr_t *bp, int flags);
static void zdb_exit(int reason);

typedef struct sublivelist_verify_block_refcnt {
	/* block pointer entry in livelist being verified */
	blkptr_t svbr_blk;

	/*
	 * Refcount gets incremented to 1 when we encounter the first
	 * FREE entry for the svfbr block pointer and a node for it
	 * is created in our ZDB verification/tracking metadata.
	 *
	 * As we encounter more FREE entries we increment this counter
	 * and similarly decrement it whenever we find the respective
	 * ALLOC entries for this block.
	 *
	 * When the refcount gets to 0 it means that all the FREE and
	 * ALLOC entries of this block have paired up and we no longer
	 * need to track it in our verification logic (e.g. the node
	 * containing this struct in our verification data structure
	 * should be freed).
	 *
	 * [refer to sublivelist_verify_blkptr() for the actual code]
	 */
	uint32_t svbr_refcnt;
} sublivelist_verify_block_refcnt_t;

static int
sublivelist_block_refcnt_compare(const void *larg, const void *rarg)
{
	const sublivelist_verify_block_refcnt_t *l = larg;
	const sublivelist_verify_block_refcnt_t *r = rarg;
	return (livelist_compare(&l->svbr_blk, &r->svbr_blk));
}

static int
sublivelist_verify_blkptr(void *arg, const blkptr_t *bp, boolean_t free,
    dmu_tx_t *tx)
{
	ASSERT0P(tx);
	struct sublivelist_verify *sv = arg;
	sublivelist_verify_block_refcnt_t current = {
			.svbr_blk = *bp,

			/*
			 * Start with 1 in case this is the first free entry.
			 * This field is not used for our B-Tree comparisons
			 * anyway.
			 */
			.svbr_refcnt = 1,
	};

	zfs_btree_index_t where;
	sublivelist_verify_block_refcnt_t *pair =
	    zfs_btree_find(&sv->sv_pair, &current, &where);
	if (free) {
		if (pair == NULL) {
			/* first free entry for this block pointer */
			zfs_btree_add(&sv->sv_pair, &current);
		} else {
			pair->svbr_refcnt++;
		}
	} else {
		if (pair == NULL) {
			/* block that is currently marked as allocated */
			for (int i = 0; i < SPA_DVAS_PER_BP; i++) {
				if (DVA_IS_EMPTY(&bp->blk_dva[i]))
					break;
				sublivelist_verify_block_t svb = {
				    .svb_dva = bp->blk_dva[i],
				    .svb_allocated_txg =
				    BP_GET_BIRTH(bp)
				};

				if (zfs_btree_find(&sv->sv_leftover, &svb,
				    &where) == NULL) {
					zfs_btree_add_idx(&sv->sv_leftover,
					    &svb, &where);
				}
			}
		} else {
			/* alloc matches a free entry */
			pair->svbr_refcnt--;
			if (pair->svbr_refcnt == 0) {
				/* all allocs and frees have been matched */
				zfs_btree_remove_idx(&sv->sv_pair, &where);
			}
		}
	}

	return (0);
}

static int
sublivelist_verify_func(void *args, dsl_deadlist_entry_t *dle)
{
	int err;
	struct sublivelist_verify *sv = args;

	zfs_btree_create(&sv->sv_pair, sublivelist_block_refcnt_compare, NULL,
	    sizeof (sublivelist_verify_block_refcnt_t));

	err = bpobj_iterate_nofree(&dle->dle_bpobj, sublivelist_verify_blkptr,
	    sv, NULL);

	sublivelist_verify_block_refcnt_t *e;
	zfs_btree_index_t *cookie = NULL;
	while ((e = zfs_btree_destroy_nodes(&sv->sv_pair, &cookie)) != NULL) {
		char blkbuf[BP_SPRINTF_LEN];
		snprintf_blkptr_compact(blkbuf, sizeof (blkbuf),
		    &e->svbr_blk, B_TRUE);
		(void) printf("\tERROR: %d unmatched FREE(s): %s\n",
		    e->svbr_refcnt, blkbuf);
		corruption_found = B_TRUE;
	}
	zfs_btree_destroy(&sv->sv_pair);

	return (err);
}

static int
livelist_block_compare(const void *larg, const void *rarg)
{
	const sublivelist_verify_block_t *l = larg;
	const sublivelist_verify_block_t *r = rarg;

	if (DVA_GET_VDEV(&l->svb_dva) < DVA_GET_VDEV(&r->svb_dva))
		return (-1);
	else if (DVA_GET_VDEV(&l->svb_dva) > DVA_GET_VDEV(&r->svb_dva))
		return (+1);

	if (DVA_GET_OFFSET(&l->svb_dva) < DVA_GET_OFFSET(&r->svb_dva))
		return (-1);
	else if (DVA_GET_OFFSET(&l->svb_dva) > DVA_GET_OFFSET(&r->svb_dva))
		return (+1);

	if (DVA_GET_ASIZE(&l->svb_dva) < DVA_GET_ASIZE(&r->svb_dva))
		return (-1);
	else if (DVA_GET_ASIZE(&l->svb_dva) > DVA_GET_ASIZE(&r->svb_dva))
		return (+1);

	return (0);
}

/*
 * Check for errors in a livelist while tracking all unfreed ALLOCs in the
 * sublivelist_verify_t: sv->sv_leftover
 */
static void
livelist_verify(dsl_deadlist_t *dl, void *arg)
{
	sublivelist_verify_t *sv = arg;
	dsl_deadlist_iterate(dl, sublivelist_verify_func, sv);
}

/*
 * Check for errors in the livelist entry and discard the intermediary
 * data structures
 */
static int
sublivelist_verify_lightweight(void *args, dsl_deadlist_entry_t *dle)
{
	(void) args;
	sublivelist_verify_t sv;
	zfs_btree_create(&sv.sv_leftover, livelist_block_compare, NULL,
	    sizeof (sublivelist_verify_block_t));
	int err = sublivelist_verify_func(&sv, dle);
	zfs_btree_clear(&sv.sv_leftover);
	zfs_btree_destroy(&sv.sv_leftover);
	return (err);
}

typedef struct metaslab_verify {
	/*
	 * Tree containing all the leftover ALLOCs from the livelists
	 * that are part of this metaslab.
	 */
	zfs_btree_t mv_livelist_allocs;

	/*
	 * Metaslab information.
	 */
	uint64_t mv_vdid;
	uint64_t mv_msid;
	uint64_t mv_start;
	uint64_t mv_end;

	/*
	 * What's currently allocated for this metaslab.
	 */
	zfs_range_tree_t *mv_allocated;
} metaslab_verify_t;

typedef void ll_iter_t(dsl_deadlist_t *ll, void *arg);

typedef int (*zdb_log_sm_cb_t)(spa_t *spa, space_map_entry_t *sme, uint64_t txg,
    void *arg);

typedef struct unflushed_iter_cb_arg {
	spa_t *uic_spa;
	uint64_t uic_txg;
	void *uic_arg;
	zdb_log_sm_cb_t uic_cb;
} unflushed_iter_cb_arg_t;

static int
iterate_through_spacemap_logs_cb(space_map_entry_t *sme, void *arg)
{
	unflushed_iter_cb_arg_t *uic = arg;
	return (uic->uic_cb(uic->uic_spa, sme, uic->uic_txg, uic->uic_arg));
}

static void
iterate_through_spacemap_logs(spa_t *spa, zdb_log_sm_cb_t cb, void *arg)
{
	if (!spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))
		return;

	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
	for (spa_log_sm_t *sls = avl_first(&spa->spa_sm_logs_by_txg);
	    sls; sls = AVL_NEXT(&spa->spa_sm_logs_by_txg, sls)) {
		space_map_t *sm = NULL;
		VERIFY0(space_map_open(&sm, spa_meta_objset(spa),
		    sls->sls_sm_obj, 0, UINT64_MAX, SPA_MINBLOCKSHIFT));

		unflushed_iter_cb_arg_t uic = {
			.uic_spa = spa,
			.uic_txg = sls->sls_txg,
			.uic_arg = arg,
			.uic_cb = cb
		};
		VERIFY0(space_map_iterate(sm, space_map_length(sm),
		    iterate_through_spacemap_logs_cb, &uic));
		space_map_close(sm);
	}
	spa_config_exit(spa, SCL_CONFIG, FTAG);
}

static void
verify_livelist_allocs(metaslab_verify_t *mv, uint64_t txg,
    uint64_t offset, uint64_t size)
{
	sublivelist_verify_block_t svb = {{{0}}};
	DVA_SET_VDEV(&svb.svb_dva, mv->mv_vdid);
	DVA_SET_OFFSET(&svb.svb_dva, offset);
	DVA_SET_ASIZE(&svb.svb_dva, size);
	zfs_btree_index_t where;
	uint64_t end_offset = offset + size;

	/*
	 *  Look for an exact match for spacemap entry in the livelist entries.
	 *  Then, look for other livelist entries that fall within the range
	 *  of the spacemap entry as it may have been condensed
	 */
	sublivelist_verify_block_t *found =
	    zfs_btree_find(&mv->mv_livelist_allocs, &svb, &where);
	if (found == NULL) {
		found = zfs_btree_next(&mv->mv_livelist_allocs, &where, &where);
	}
	for (; found != NULL && DVA_GET_VDEV(&found->svb_dva) == mv->mv_vdid &&
	    DVA_GET_OFFSET(&found->svb_dva) < end_offset;
	    found = zfs_btree_next(&mv->mv_livelist_allocs, &where, &where)) {
		if (found->svb_allocated_txg <= txg) {
			(void) printf("ERROR: Livelist ALLOC [%llx:%llx] "
			    "from TXG %llx FREED at TXG %llx\n",
			    (u_longlong_t)DVA_GET_OFFSET(&found->svb_dva),
			    (u_longlong_t)DVA_GET_ASIZE(&found->svb_dva),
			    (u_longlong_t)found->svb_allocated_txg,
			    (u_longlong_t)txg);
			corruption_found = B_TRUE;
		}
	}
}

static int
metaslab_spacemap_validation_cb(space_map_entry_t *sme, void *arg)
{
	metaslab_verify_t *mv = arg;
	uint64_t offset = sme->sme_offset;
	uint64_t size = sme->sme_run;
	uint64_t txg = sme->sme_txg;

	if (sme->sme_type == SM_ALLOC) {
		if (zfs_range_tree_contains(mv->mv_allocated,
		    offset, size)) {
			(void) printf("ERROR: DOUBLE ALLOC: "
			    "%llu [%llx:%llx] "
			    "%llu:%llu LOG_SM\n",
			    (u_longlong_t)txg, (u_longlong_t)offset,
			    (u_longlong_t)size, (u_longlong_t)mv->mv_vdid,
			    (u_longlong_t)mv->mv_msid);
			corruption_found = B_TRUE;
		} else {
			zfs_range_tree_add(mv->mv_allocated,
			    offset, size);
		}
	} else {
		if (!zfs_range_tree_contains(mv->mv_allocated,
		    offset, size)) {
			(void) printf("ERROR: DOUBLE FREE: "
			    "%llu [%llx:%llx] "
			    "%llu:%llu LOG_SM\n",
			    (u_longlong_t)txg, (u_longlong_t)offset,
			    (u_longlong_t)size, (u_longlong_t)mv->mv_vdid,
			    (u_longlong_t)mv->mv_msid);
			corruption_found = B_TRUE;
		} else {
			zfs_range_tree_remove(mv->mv_allocated,
			    offset, size);
		}
	}

	if (sme->sme_type != SM_ALLOC) {
		/*
		 * If something is freed in the spacemap, verify that
		 * it is not listed as allocated in the livelist.
		 */
		verify_livelist_allocs(mv, txg, offset, size);
	}
	return (0);
}

static int
spacemap_check_sm_log_cb(spa_t *spa, space_map_entry_t *sme,
    uint64_t txg, void *arg)
{
	metaslab_verify_t *mv = arg;
	uint64_t offset = sme->sme_offset;
	uint64_t vdev_id = sme->sme_vdev;

	vdev_t *vd = vdev_lookup_top(spa, vdev_id);

	/* skip indirect vdevs */
	if (!vdev_is_concrete(vd))
		return (0);

	if (vdev_id != mv->mv_vdid)
		return (0);

	metaslab_t *ms = vd->vdev_ms[offset >> vd->vdev_ms_shift];
	if (ms->ms_id != mv->mv_msid)
		return (0);

	if (txg < metaslab_unflushed_txg(ms))
		return (0);


	ASSERT3U(txg, ==, sme->sme_txg);
	return (metaslab_spacemap_validation_cb(sme, mv));
}

static void
spacemap_check_sm_log(spa_t *spa, metaslab_verify_t *mv)
{
	iterate_through_spacemap_logs(spa, spacemap_check_sm_log_cb, mv);
}

static void
spacemap_check_ms_sm(space_map_t  *sm, metaslab_verify_t *mv)
{
	if (sm == NULL)
		return;

	VERIFY0(space_map_iterate(sm, space_map_length(sm),
	    metaslab_spacemap_validation_cb, mv));
}

static void iterate_deleted_livelists(spa_t *spa, ll_iter_t func, void *arg);

/*
 * Transfer blocks from sv_leftover tree to the mv_livelist_allocs if
 * they are part of that metaslab (mv_msid).
 */
static void
mv_populate_livelist_allocs(metaslab_verify_t *mv, sublivelist_verify_t *sv)
{
	zfs_btree_index_t where;
	sublivelist_verify_block_t *svb;
	ASSERT3U(zfs_btree_numnodes(&mv->mv_livelist_allocs), ==, 0);
	for (svb = zfs_btree_first(&sv->sv_leftover, &where);
	    svb != NULL;
	    svb = zfs_btree_next(&sv->sv_leftover, &where, &where)) {
		if (DVA_GET_VDEV(&svb->svb_dva) != mv->mv_vdid)
			continue;

		if (DVA_GET_OFFSET(&svb->svb_dva) < mv->mv_start &&
		    (DVA_GET_OFFSET(&svb->svb_dva) +
		    DVA_GET_ASIZE(&svb->svb_dva)) > mv->mv_start) {
			(void) printf("ERROR: Found block that crosses "
			    "metaslab boundary: <%llu:%llx:%llx>\n",
			    (u_longlong_t)DVA_GET_VDEV(&svb->svb_dva),
			    (u_longlong_t)DVA_GET_OFFSET(&svb->svb_dva),
			    (u_longlong_t)DVA_GET_ASIZE(&svb->svb_dva));
			corruption_found = B_TRUE;
			continue;
		}

		if (DVA_GET_OFFSET(&svb->svb_dva) < mv->mv_start)
			continue;

		if (DVA_GET_OFFSET(&svb->svb_dva) >= mv->mv_end)
			continue;

		if ((DVA_GET_OFFSET(&svb->svb_dva) +
		    DVA_GET_ASIZE(&svb->svb_dva)) > mv->mv_end) {
			(void) printf("ERROR: Found block that crosses "
			    "metaslab boundary: <%llu:%llx:%llx>\n",
			    (u_longlong_t)DVA_GET_VDEV(&svb->svb_dva),
			    (u_longlong_t)DVA_GET_OFFSET(&svb->svb_dva),
			    (u_longlong_t)DVA_GET_ASIZE(&svb->svb_dva));
			corruption_found = B_TRUE;
			continue;
		}

		zfs_btree_add(&mv->mv_livelist_allocs, svb);
	}

	for (svb = zfs_btree_first(&mv->mv_livelist_allocs, &where);
	    svb != NULL;
	    svb = zfs_btree_next(&mv->mv_livelist_allocs, &where, &where)) {
		zfs_btree_remove(&sv->sv_leftover, svb);
	}
}

/*
 * [Livelist Check]
 * Iterate through all the sublivelists and:
 * - report leftover frees (**)
 * - record leftover ALLOCs together with their TXG [see Cross Check]
 *
 * (**) Note: Double ALLOCs are valid in datasets that have dedup
 *      enabled. Similarly double FREEs are allowed as well but
 *      only if they pair up with a corresponding ALLOC entry once
 *      we our done with our sublivelist iteration.
 *
 * [Spacemap Check]
 * for each metaslab:
 * - iterate over spacemap and then the metaslab's entries in the
 *   spacemap log, then report any double FREEs and ALLOCs (do not
 *   blow up).
 *
 * [Cross Check]
 * After finishing the Livelist Check phase and while being in the
 * Spacemap Check phase, we find all the recorded leftover ALLOCs
 * of the livelist check that are part of the metaslab that we are
 * currently looking at in the Spacemap Check. We report any entries
 * that are marked as ALLOCs in the livelists but have been actually
 * freed (and potentially allocated again) after their TXG stamp in
 * the spacemaps. Also report any ALLOCs from the livelists that
 * belong to indirect vdevs (e.g. their vdev completed removal).
 *
 * Note that this will miss Log Spacemap entries that cancelled each other
 * out before being flushed to the metaslab, so we are not guaranteed
 * to match all erroneous ALLOCs.
 */
static void
livelist_metaslab_validate(spa_t *spa)
{
	(void) printf("Verifying deleted livelist entries\n");

	sublivelist_verify_t sv;
	zfs_btree_create(&sv.sv_leftover, livelist_block_compare, NULL,
	    sizeof (sublivelist_verify_block_t));
	iterate_deleted_livelists(spa, livelist_verify, &sv);

	(void) printf("Verifying metaslab entries\n");
	vdev_t *rvd = spa->spa_root_vdev;
	for (uint64_t c = 0; c < rvd->vdev_children; c++) {
		vdev_t *vd = rvd->vdev_child[c];

		if (!vdev_is_concrete(vd))
			continue;

		for (uint64_t mid = 0; mid < vd->vdev_ms_count; mid++) {
			metaslab_t *m = vd->vdev_ms[mid];

			(void) fprintf(stderr,
			    "\rverifying concrete vdev %llu, "
			    "metaslab %llu of %llu ...",
			    (longlong_t)vd->vdev_id,
			    (longlong_t)mid,
			    (longlong_t)vd->vdev_ms_count);

			uint64_t shift, start;
			zfs_range_seg_type_t type =
			    metaslab_calculate_range_tree_type(vd, m,
			    &start, &shift);
			metaslab_verify_t mv;
			mv.mv_allocated = zfs_range_tree_create_flags(
			    NULL, type, NULL, start, shift,
			    0, "livelist_metaslab_validate:mv_allocated");
			mv.mv_vdid = vd->vdev_id;
			mv.mv_msid = m->ms_id;
			mv.mv_start = m->ms_start;
			mv.mv_end = m->ms_start + m->ms_size;
			zfs_btree_create(&mv.mv_livelist_allocs,
			    livelist_block_compare, NULL,
			    sizeof (sublivelist_verify_block_t));

			mv_populate_livelist_allocs(&mv, &sv);

			spacemap_check_ms_sm(m->ms_sm, &mv);
			spacemap_check_sm_log(spa, &mv);

			zfs_range_tree_vacate(mv.mv_allocated, NULL, NULL);
			zfs_range_tree_destroy(mv.mv_allocated);
			zfs_btree_clear(&mv.mv_livelist_allocs);
			zfs_btree_destroy(&mv.mv_livelist_allocs);
		}
	}
	(void) fprintf(stderr, "\n");

	/*
	 * If there are any segments in the leftover tree after we walked
	 * through all the metaslabs in the concrete vdevs then this means
	 * that we have segments in the livelists that belong to indirect
	 * vdevs and are marked as allocated.
	 */
	if (zfs_btree_numnodes(&sv.sv_leftover) == 0) {
		zfs_btree_destroy(&sv.sv_leftover);
		return;
	}
	(void) printf("ERROR: Found livelist blocks marked as allocated "
	    "for indirect vdevs:\n");
	corruption_found = B_TRUE;

	zfs_btree_index_t *where = NULL;
	sublivelist_verify_block_t *svb;
	while ((svb = zfs_btree_destroy_nodes(&sv.sv_leftover, &where)) !=
	    NULL) {
		int vdev_id = DVA_GET_VDEV(&svb->svb_dva);
		ASSERT3U(vdev_id, <, rvd->vdev_children);
		vdev_t *vd = rvd->vdev_child[vdev_id];
		ASSERT(!vdev_is_concrete(vd));
		(void) printf("<%d:%llx:%llx> TXG %llx\n",
		    vdev_id, (u_longlong_t)DVA_GET_OFFSET(&svb->svb_dva),
		    (u_longlong_t)DVA_GET_ASIZE(&svb->svb_dva),
		    (u_longlong_t)svb->svb_allocated_txg);
	}
	(void) printf("\n");
	zfs_btree_destroy(&sv.sv_leftover);
}

/*
 * These libumem hooks provide a reasonable set of defaults for the allocator's
 * debugging facilities.
 */
const char *
_umem_debug_init(void)
{
	return ("default,verbose"); /* $UMEM_DEBUG setting */
}

const char *
_umem_logging_init(void)
{
	return ("fail,contents"); /* $UMEM_LOGGING setting */
}

static void
usage(void)
{
	(void) fprintf(stderr,
	    "Usage:\t%s [-AbcdDFGhikLMPsvXy] [-e [-V] [-p <path> ...]] "
	    "[-I <inflight I/Os>]\n"
	    "\t\t[-o <var>=<value>]... [-t <txg>] [-U <cache>] [-x <dumpdir>]\n"
	    "\t\t[-K <key>]\n"
	    "\t\t[<poolname>[/<dataset | objset id>] [<object | range> ...]]\n"
	    "\t%s [-AdiPv] [-e [-V] [-p <path> ...]] [-U <cache>] [-K <key>]\n"
	    "\t\t[<poolname>[/<dataset | objset id>] [<object | range> ...]\n"
	    "\t%s -B [-e [-V] [-p <path> ...]] [-I <inflight I/Os>]\n"
	    "\t\t[-o <var>=<value>]... [-t <txg>] [-U <cache>] [-x <dumpdir>]\n"
	    "\t\t[-K <key>] <poolname>/<objset id> [<backupflags>]\n"
	    "\t%s [-v] <bookmark>\n"
	    "\t%s -C [-A] [-U <cache>] [<poolname>]\n"
	    "\t%s -l [-Aqu] <device>\n"
	    "\t%s -m [-AFLPX] [-e [-V] [-p <path> ...]] [-t <txg>] "
	    "[-U <cache>]\n\t\t<poolname> [<vdev> [<metaslab> ...]]\n"
	    "\t%s -O [-K <key>] <dataset> <path>\n"
	    "\t%s -r [-K <key>] <dataset> <path> <destination>\n"
	    "\t%s -R [-A] [-e [-V] [-p <path> ...]] [-U <cache>]\n"
	    "\t\t<poolname> <vdev>:<offset>:<size>[:<flags>]\n"
	    "\t%s -E [-A] word0:word1:...:word15\n"
	    "\t%s -S [-AP] [-e [-V] [-p <path> ...]] [-U <cache>] "
	    "<poolname>\n\n",
	    cmdname, cmdname, cmdname, cmdname, cmdname, cmdname, cmdname,
	    cmdname, cmdname, cmdname, cmdname, cmdname);

	(void) fprintf(stderr, "    Dataset name must include at least one "
	    "separator character '/' or '@'\n");
	(void) fprintf(stderr, "    If dataset name is specified, only that "
	    "dataset is dumped\n");
	(void) fprintf(stderr,  "    If object numbers or object number "
	    "ranges are specified, only those\n"
	    "    objects or ranges are dumped.\n\n");
	(void) fprintf(stderr,
	    "    Object ranges take the form <start>:<end>[:<flags>]\n"
	    "        start    Starting object number\n"
	    "        end      Ending object number, or -1 for no upper bound\n"
	    "        flags    Optional flags to select object types:\n"
	    "            A     All objects (this is the default)\n"
	    "            d     ZFS directories\n"
	    "            f     ZFS files \n"
	    "            m     SPA space maps\n"
	    "            z     ZAPs\n"
	    "            -     Negate effect of next flag\n\n");
	(void) fprintf(stderr, "    Options to control amount of output:\n");
	(void) fprintf(stderr, "        -b --block-stats             "
	    "block statistics\n");
	(void) fprintf(stderr, "        -B --backup                  "
	    "backup stream\n");
	(void) fprintf(stderr, "        -c --checksum                "
	    "checksum all metadata (twice for all data) blocks\n");
	(void) fprintf(stderr, "        -C --config                  "
	    "config (or cachefile if alone)\n");
	(void) fprintf(stderr, "        -d --datasets                "
	    "dataset(s)\n");
	(void) fprintf(stderr, "        -D --dedup-stats             "
	    "dedup statistics\n");
	(void) fprintf(stderr, "        -E --embedded-block-pointer=INTEGER\n"
	    "                                     decode and display block "
	    "from an embedded block pointer\n");
	(void) fprintf(stderr, "        -h --history                 "
	    "pool history\n");
	(void) fprintf(stderr, "        -i --intent-logs             "
	    "intent logs\n");
	(void) fprintf(stderr, "        -l --label                   "
	    "read label contents\n");
	(void) fprintf(stderr, "        -k --checkpointed-state      "
	    "examine the checkpointed state of the pool\n");
	(void) fprintf(stderr, "        -L --disable-leak-tracking   "
	    "disable leak tracking (do not load spacemaps)\n");
	(void) fprintf(stderr, "        -m --metaslabs               "
	    "metaslabs\n");
	(void) fprintf(stderr, "        -M --metaslab-groups         "
	    "metaslab groups\n");
	(void) fprintf(stderr, "        -O --object-lookups          "
	    "perform object lookups by path\n");
	(void) fprintf(stderr, "        -r --copy-object             "
	    "copy an object by path to file\n");
	(void) fprintf(stderr, "        -R --read-block              "
	    "read and display block from a device\n");
	(void) fprintf(stderr, "        -s --io-stats                "
	    "report stats on zdb's I/O\n");
	(void) fprintf(stderr, "        -S --simulate-dedup          "
	    "simulate dedup to measure effect\n");
	(void) fprintf(stderr, "        -v --verbose                 "
	    "verbose (applies to all others)\n");
	(void) fprintf(stderr, "        -y --livelist                "
	    "perform livelist and metaslab validation on any livelists being "
	    "deleted\n\n");
	(void) fprintf(stderr, "    Below options are intended for use "
	    "with other options:\n");
	(void) fprintf(stderr, "        -A --ignore-assertions       "
	    "ignore assertions (-A), enable panic recovery (-AA) or both "
	    "(-AAA)\n");
	(void) fprintf(stderr, "        -e --exported                "
	    "pool is exported/destroyed/has altroot/not in a cachefile\n");
	(void) fprintf(stderr, "        -F --automatic-rewind        "
	    "attempt automatic rewind within safe range of transaction "
	    "groups\n");
	(void) fprintf(stderr, "        -G --dump-debug-msg          "
	    "dump zfs_dbgmsg buffer before exiting\n");
	(void) fprintf(stderr, "        -I --inflight=INTEGER        "
	    "specify the maximum number of checksumming I/Os "
	    "[default is 200]\n");
	(void) fprintf(stderr, "        -K --key=KEY                 "
	    "decryption key for encrypted dataset\n");
	(void) fprintf(stderr, "        -o --option=\"NAME=VALUE\" "
	    "set the named tunable to the given value\n");
	(void) fprintf(stderr, "        -p --path==PATH              "
	    "use one or more with -e to specify path to vdev dir\n");
	(void) fprintf(stderr, "        -P --parseable               "
	    "print numbers in parseable form\n");
	(void) fprintf(stderr, "        -q --skip-label              "
	    "don't print label contents\n");
	(void) fprintf(stderr, "        -t --txg=INTEGER             "
	    "highest txg to use when searching for uberblocks\n");
	(void) fprintf(stderr, "        -T --brt-stats               "
	    "BRT statistics\n");
	(void) fprintf(stderr, "        -u --uberblock               "
	    "uberblock\n");
	(void) fprintf(stderr, "        -U --cachefile=PATH          "
	    "use alternate cachefile\n");
	(void) fprintf(stderr, "        -V --verbatim                "
	    "do verbatim import\n");
	(void) fprintf(stderr, "        -x --dump-blocks=PATH        "
	    "dump all read blocks into specified directory\n");
	(void) fprintf(stderr, "        -X --extreme-rewind          "
	    "attempt extreme rewind (does not work with dataset)\n");
	(void) fprintf(stderr, "        -Y --all-reconstruction      "
	    "attempt all reconstruction combinations for split blocks\n");
	(void) fprintf(stderr, "        -Z --zstd-headers            "
	    "show ZSTD headers \n");
	(void) fprintf(stderr, "Specify an option more than once (e.g. -bb) "
	    "to make only that option verbose\n");
	(void) fprintf(stderr, "Default is to dump everything non-verbosely\n");
	zdb_exit(2);
}

static void
dump_debug_buffer(void)
{
	ssize_t ret __attribute__((unused));

	if (!dump_opt['G'])
		return;
	/*
	 * We use write() instead of printf() so that this function
	 * is safe to call from a signal handler.
	 */
	ret = write(STDERR_FILENO, "\n", 1);
	zfs_dbgmsg_print(STDERR_FILENO, "zdb");
}

static void sig_handler(int signo)
{
	struct sigaction action;

	libspl_backtrace(STDERR_FILENO);
	dump_debug_buffer();

	/*
	 * Restore default action and re-raise signal so SIGSEGV and
	 * SIGABRT can trigger a core dump.
	 */
	action.sa_handler = SIG_DFL;
	sigemptyset(&action.sa_mask);
	action.sa_flags = 0;
	(void) sigaction(signo, &action, NULL);
	raise(signo);
}

/*
 * Called for usage errors that are discovered after a call to spa_open(),
 * dmu_bonus_hold(), or pool_match().  abort() is called for other errors.
 */

static void
fatal(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	(void) fprintf(stderr, "%s: ", cmdname);
	(void) vfprintf(stderr, fmt, ap);
	va_end(ap);
	(void) fprintf(stderr, "\n");

	dump_debug_buffer();

	zdb_exit(1);
}

static void
dump_packed_nvlist(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) size;
	nvlist_t *nv;
	size_t nvsize = *(uint64_t *)data;
	char *packed = umem_alloc(nvsize, UMEM_NOFAIL);

	VERIFY0(dmu_read(os, object, 0, nvsize, packed, DMU_READ_PREFETCH));

	VERIFY0(nvlist_unpack(packed, nvsize, &nv, 0));

	umem_free(packed, nvsize);

	dump_nvlist(nv, 8);

	nvlist_free(nv);
}

static void
dump_history_offsets(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) size;
	spa_history_phys_t *shp = data;

	if (shp == NULL)
		return;

	(void) printf("\t\tpool_create_len = %llu\n",
	    (u_longlong_t)shp->sh_pool_create_len);
	(void) printf("\t\tphys_max_off = %llu\n",
	    (u_longlong_t)shp->sh_phys_max_off);
	(void) printf("\t\tbof = %llu\n",
	    (u_longlong_t)shp->sh_bof);
	(void) printf("\t\teof = %llu\n",
	    (u_longlong_t)shp->sh_eof);
	(void) printf("\t\trecords_lost = %llu\n",
	    (u_longlong_t)shp->sh_records_lost);
}

static void
zdb_nicenum(uint64_t num, char *buf, size_t buflen)
{
	if (dump_opt['P'])
		(void) snprintf(buf, buflen, "%llu", (longlong_t)num);
	else
		nicenum(num, buf, buflen);
}

static void
zdb_nicebytes(uint64_t bytes, char *buf, size_t buflen)
{
	if (dump_opt['P'])
		(void) snprintf(buf, buflen, "%llu", (longlong_t)bytes);
	else
		zfs_nicebytes(bytes, buf, buflen);
}

static const char histo_stars[] = "****************************************";
static const uint64_t histo_width = sizeof (histo_stars) - 1;

static void
dump_histogram(const uint64_t *histo, int size, int offset)
{
	int i;
	int minidx = size - 1;
	int maxidx = 0;
	uint64_t max = 0;

	for (i = 0; i < size; i++) {
		if (histo[i] == 0)
			continue;
		if (histo[i] > max)
			max = histo[i];
		if (i > maxidx)
			maxidx = i;
		if (i < minidx)
			minidx = i;
	}

	if (max < histo_width)
		max = histo_width;

	for (i = minidx; i <= maxidx; i++) {
		(void) printf("\t\t\t%3u: %6llu %s\n",
		    i + offset, (u_longlong_t)histo[i],
		    &histo_stars[(max - histo[i]) * histo_width / max]);
	}
}

static void
dump_zap_stats(objset_t *os, uint64_t object)
{
	int error;
	zap_stats_t zs;

	error = zap_get_stats(os, object, &zs);
	if (error)
		return;

	if (zs.zs_ptrtbl_len == 0) {
		ASSERT(zs.zs_num_blocks == 1);
		(void) printf("\tmicrozap: %llu bytes, %llu entries\n",
		    (u_longlong_t)zs.zs_blocksize,
		    (u_longlong_t)zs.zs_num_entries);
		return;
	}

	(void) printf("\tFat ZAP stats:\n");

	(void) printf("\t\tPointer table:\n");
	(void) printf("\t\t\t%llu elements\n",
	    (u_longlong_t)zs.zs_ptrtbl_len);
	(void) printf("\t\t\tzt_blk: %llu\n",
	    (u_longlong_t)zs.zs_ptrtbl_zt_blk);
	(void) printf("\t\t\tzt_numblks: %llu\n",
	    (u_longlong_t)zs.zs_ptrtbl_zt_numblks);
	(void) printf("\t\t\tzt_shift: %llu\n",
	    (u_longlong_t)zs.zs_ptrtbl_zt_shift);
	(void) printf("\t\t\tzt_blks_copied: %llu\n",
	    (u_longlong_t)zs.zs_ptrtbl_blks_copied);
	(void) printf("\t\t\tzt_nextblk: %llu\n",
	    (u_longlong_t)zs.zs_ptrtbl_nextblk);

	(void) printf("\t\tZAP entries: %llu\n",
	    (u_longlong_t)zs.zs_num_entries);
	(void) printf("\t\tLeaf blocks: %llu\n",
	    (u_longlong_t)zs.zs_num_leafs);
	(void) printf("\t\tTotal blocks: %llu\n",
	    (u_longlong_t)zs.zs_num_blocks);
	(void) printf("\t\tzap_block_type: 0x%llx\n",
	    (u_longlong_t)zs.zs_block_type);
	(void) printf("\t\tzap_magic: 0x%llx\n",
	    (u_longlong_t)zs.zs_magic);
	(void) printf("\t\tzap_salt: 0x%llx\n",
	    (u_longlong_t)zs.zs_salt);

	(void) printf("\t\tLeafs with 2^n pointers:\n");
	dump_histogram(zs.zs_leafs_with_2n_pointers, ZAP_HISTOGRAM_SIZE, 0);

	(void) printf("\t\tBlocks with n*5 entries:\n");
	dump_histogram(zs.zs_blocks_with_n5_entries, ZAP_HISTOGRAM_SIZE, 0);

	(void) printf("\t\tBlocks n/10 full:\n");
	dump_histogram(zs.zs_blocks_n_tenths_full, ZAP_HISTOGRAM_SIZE, 0);

	(void) printf("\t\tEntries with n chunks:\n");
	dump_histogram(zs.zs_entries_using_n_chunks, ZAP_HISTOGRAM_SIZE, 0);

	(void) printf("\t\tBuckets with n entries:\n");
	dump_histogram(zs.zs_buckets_with_n_entries, ZAP_HISTOGRAM_SIZE, 0);
}

static void
dump_none(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) data, (void) size;
}

static void
dump_unknown(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) data, (void) size;
	(void) printf("\tUNKNOWN OBJECT TYPE\n");
}

static void
dump_uint8(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) data, (void) size;
}

static void
dump_uint64(objset_t *os, uint64_t object, void *data, size_t size)
{
	uint64_t *arr;
	uint64_t oursize;
	if (dump_opt['d'] < 6)
		return;

	if (data == NULL) {
		dmu_object_info_t doi;

		VERIFY0(dmu_object_info(os, object, &doi));
		size = doi.doi_max_offset;
		/*
		 * We cap the size at 1 mebibyte here to prevent
		 * allocation failures and nigh-infinite printing if the
		 * object is extremely large.
		 */
		oursize = MIN(size, 1 << 20);
		arr = kmem_alloc(oursize, KM_SLEEP);

		int err = dmu_read(os, object, 0, oursize, arr, 0);
		if (err != 0) {
			(void) printf("got error %u from dmu_read\n", err);
			kmem_free(arr, oursize);
			return;
		}
	} else {
		/*
		 * Even though the allocation is already done in this code path,
		 * we still cap the size to prevent excessive printing.
		 */
		oursize = MIN(size, 1 << 20);
		arr = data;
	}

	if (size == 0) {
		if (data == NULL)
			kmem_free(arr, oursize);
		(void) printf("\t\t[]\n");
		return;
	}

	(void) printf("\t\t[%0llx", (u_longlong_t)arr[0]);
	for (size_t i = 1; i * sizeof (uint64_t) < oursize; i++) {
		if (i % 4 != 0)
			(void) printf(", %0llx", (u_longlong_t)arr[i]);
		else
			(void) printf(",\n\t\t%0llx", (u_longlong_t)arr[i]);
	}
	if (oursize != size)
		(void) printf(", ... ");
	(void) printf("]\n");

	if (data == NULL)
		kmem_free(arr, oursize);
}

static void
dump_zap(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	zap_cursor_t zc;
	zap_attribute_t *attrp = zap_attribute_long_alloc();
	void *prop;
	unsigned i;

	dump_zap_stats(os, object);
	(void) printf("\n");

	for (zap_cursor_init(&zc, os, object);
	    zap_cursor_retrieve(&zc, attrp) == 0;
	    zap_cursor_advance(&zc)) {
		boolean_t key64 =
		    !!(zap_getflags(zc.zc_zap) & ZAP_FLAG_UINT64_KEY);

		if (key64)
			(void) printf("\t\t0x%010" PRIu64 "x = ",
			    *(uint64_t *)attrp->za_name);
		else
			(void) printf("\t\t%s = ", attrp->za_name);

		if (attrp->za_num_integers == 0) {
			(void) printf("\n");
			continue;
		}
		prop = umem_zalloc(attrp->za_num_integers *
		    attrp->za_integer_length, UMEM_NOFAIL);

		if (key64)
			(void) zap_lookup_uint64(os, object,
			    (const uint64_t *)attrp->za_name, 1,
			    attrp->za_integer_length, attrp->za_num_integers,
			    prop);
		else
			(void) zap_lookup(os, object, attrp->za_name,
			    attrp->za_integer_length, attrp->za_num_integers,
			    prop);

		if (attrp->za_integer_length == 1 && !key64) {
			if (strcmp(attrp->za_name,
			    DSL_CRYPTO_KEY_MASTER_KEY) == 0 ||
			    strcmp(attrp->za_name,
			    DSL_CRYPTO_KEY_HMAC_KEY) == 0 ||
			    strcmp(attrp->za_name, DSL_CRYPTO_KEY_IV) == 0 ||
			    strcmp(attrp->za_name, DSL_CRYPTO_KEY_MAC) == 0 ||
			    strcmp(attrp->za_name,
			    DMU_POOL_CHECKSUM_SALT) == 0) {
				uint8_t *u8 = prop;

				for (i = 0; i < attrp->za_num_integers; i++) {
					(void) printf("%02x", u8[i]);
				}
			} else {
				(void) printf("%s", (char *)prop);
			}
		} else {
			for (i = 0; i < attrp->za_num_integers; i++) {
				switch (attrp->za_integer_length) {
				case 1:
					(void) printf("%u ",
					    ((uint8_t *)prop)[i]);
					break;
				case 2:
					(void) printf("%u ",
					    ((uint16_t *)prop)[i]);
					break;
				case 4:
					(void) printf("%u ",
					    ((uint32_t *)prop)[i]);
					break;
				case 8:
					(void) printf("%lld ",
					    (u_longlong_t)((int64_t *)prop)[i]);
					break;
				}
			}
		}
		(void) printf("\n");
		umem_free(prop,
		    attrp->za_num_integers * attrp->za_integer_length);
	}
	zap_cursor_fini(&zc);
	zap_attribute_free(attrp);
}

static void
dump_bpobj(objset_t *os, uint64_t object, void *data, size_t size)
{
	bpobj_phys_t *bpop = data;
	uint64_t i;
	char bytes[32], comp[32], uncomp[32];

	/* make sure the output won't get truncated */
	_Static_assert(sizeof (bytes) >= NN_NUMBUF_SZ, "bytes truncated");
	_Static_assert(sizeof (comp) >= NN_NUMBUF_SZ, "comp truncated");
	_Static_assert(sizeof (uncomp) >= NN_NUMBUF_SZ, "uncomp truncated");

	if (bpop == NULL)
		return;

	zdb_nicenum(bpop->bpo_bytes, bytes, sizeof (bytes));
	zdb_nicenum(bpop->bpo_comp, comp, sizeof (comp));
	zdb_nicenum(bpop->bpo_uncomp, uncomp, sizeof (uncomp));

	(void) printf("\t\tnum_blkptrs = %llu\n",
	    (u_longlong_t)bpop->bpo_num_blkptrs);
	(void) printf("\t\tbytes = %s\n", bytes);
	if (size >= BPOBJ_SIZE_V1) {
		(void) printf("\t\tcomp = %s\n", comp);
		(void) printf("\t\tuncomp = %s\n", uncomp);
	}
	if (size >= BPOBJ_SIZE_V2) {
		(void) printf("\t\tsubobjs = %llu\n",
		    (u_longlong_t)bpop->bpo_subobjs);
		(void) printf("\t\tnum_subobjs = %llu\n",
		    (u_longlong_t)bpop->bpo_num_subobjs);
	}
	if (size >= sizeof (*bpop)) {
		(void) printf("\t\tnum_freed = %llu\n",
		    (u_longlong_t)bpop->bpo_num_freed);
	}

	if (dump_opt['d'] < 5)
		return;

	for (i = 0; i < bpop->bpo_num_blkptrs; i++) {
		char blkbuf[BP_SPRINTF_LEN];
		blkptr_t bp;

		int err = dmu_read(os, object,
		    i * sizeof (bp), sizeof (bp), &bp, 0);
		if (err != 0) {
			(void) printf("got error %u from dmu_read\n", err);
			break;
		}
		snprintf_blkptr_compact(blkbuf, sizeof (blkbuf), &bp,
		    BP_GET_FREE(&bp));
		(void) printf("\t%s\n", blkbuf);
	}
}

static void
dump_bpobj_subobjs(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	dmu_object_info_t doi;
	int64_t i;

	VERIFY0(dmu_object_info(os, object, &doi));
	uint64_t *subobjs = kmem_alloc(doi.doi_max_offset, KM_SLEEP);

	int err = dmu_read(os, object, 0, doi.doi_max_offset, subobjs, 0);
	if (err != 0) {
		(void) printf("got error %u from dmu_read\n", err);
		kmem_free(subobjs, doi.doi_max_offset);
		return;
	}

	int64_t last_nonzero = -1;
	for (i = 0; i < doi.doi_max_offset / 8; i++) {
		if (subobjs[i] != 0)
			last_nonzero = i;
	}

	for (i = 0; i <= last_nonzero; i++) {
		(void) printf("\t%llu\n", (u_longlong_t)subobjs[i]);
	}
	kmem_free(subobjs, doi.doi_max_offset);
}

static void
dump_ddt_zap(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	dump_zap_stats(os, object);
	/* contents are printed elsewhere, properly decoded */
}

static void
dump_sa_attrs(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	zap_cursor_t zc;
	zap_attribute_t *attrp = zap_attribute_alloc();

	dump_zap_stats(os, object);
	(void) printf("\n");

	for (zap_cursor_init(&zc, os, object);
	    zap_cursor_retrieve(&zc, attrp) == 0;
	    zap_cursor_advance(&zc)) {
		(void) printf("\t\t%s = ", attrp->za_name);
		if (attrp->za_num_integers == 0) {
			(void) printf("\n");
			continue;
		}
		(void) printf(" %llx : [%d:%d:%d]\n",
		    (u_longlong_t)attrp->za_first_integer,
		    (int)ATTR_LENGTH(attrp->za_first_integer),
		    (int)ATTR_BSWAP(attrp->za_first_integer),
		    (int)ATTR_NUM(attrp->za_first_integer));
	}
	zap_cursor_fini(&zc);
	zap_attribute_free(attrp);
}

static void
dump_sa_layouts(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	zap_cursor_t zc;
	zap_attribute_t *attrp = zap_attribute_alloc();
	uint16_t *layout_attrs;
	unsigned i;

	dump_zap_stats(os, object);
	(void) printf("\n");

	for (zap_cursor_init(&zc, os, object);
	    zap_cursor_retrieve(&zc, attrp) == 0;
	    zap_cursor_advance(&zc)) {
		(void) printf("\t\t%s = [", attrp->za_name);
		if (attrp->za_num_integers == 0) {
			(void) printf("\n");
			continue;
		}

		VERIFY(attrp->za_integer_length == 2);
		layout_attrs = umem_zalloc(attrp->za_num_integers *
		    attrp->za_integer_length, UMEM_NOFAIL);

		VERIFY(zap_lookup(os, object, attrp->za_name,
		    attrp->za_integer_length,
		    attrp->za_num_integers, layout_attrs) == 0);

		for (i = 0; i != attrp->za_num_integers; i++)
			(void) printf(" %d ", (int)layout_attrs[i]);
		(void) printf("]\n");
		umem_free(layout_attrs,
		    attrp->za_num_integers * attrp->za_integer_length);
	}
	zap_cursor_fini(&zc);
	zap_attribute_free(attrp);
}

static void
dump_zpldir(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	zap_cursor_t zc;
	zap_attribute_t *attrp = zap_attribute_long_alloc();
	const char *typenames[] = {
		/* 0 */ "not specified",
		/* 1 */ "FIFO",
		/* 2 */ "Character Device",
		/* 3 */ "3 (invalid)",
		/* 4 */ "Directory",
		/* 5 */ "5 (invalid)",
		/* 6 */ "Block Device",
		/* 7 */ "7 (invalid)",
		/* 8 */ "Regular File",
		/* 9 */ "9 (invalid)",
		/* 10 */ "Symbolic Link",
		/* 11 */ "11 (invalid)",
		/* 12 */ "Socket",
		/* 13 */ "Door",
		/* 14 */ "Event Port",
		/* 15 */ "15 (invalid)",
	};

	dump_zap_stats(os, object);
	(void) printf("\n");

	for (zap_cursor_init(&zc, os, object);
	    zap_cursor_retrieve(&zc, attrp) == 0;
	    zap_cursor_advance(&zc)) {
		(void) printf("\t\t%s = %lld (type: %s)\n",
		    attrp->za_name, ZFS_DIRENT_OBJ(attrp->za_first_integer),
		    typenames[ZFS_DIRENT_TYPE(attrp->za_first_integer)]);
	}
	zap_cursor_fini(&zc);
	zap_attribute_free(attrp);
}

static int
get_dtl_refcount(vdev_t *vd)
{
	int refcount = 0;

	if (vd->vdev_ops->vdev_op_leaf) {
		space_map_t *sm = vd->vdev_dtl_sm;

		if (sm != NULL &&
		    sm->sm_dbuf->db_size == sizeof (space_map_phys_t))
			return (1);
		return (0);
	}

	for (unsigned c = 0; c < vd->vdev_children; c++)
		refcount += get_dtl_refcount(vd->vdev_child[c]);
	return (refcount);
}

static int
get_metaslab_refcount(vdev_t *vd)
{
	int refcount = 0;

	if (vd->vdev_top == vd) {
		for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {
			space_map_t *sm = vd->vdev_ms[m]->ms_sm;

			if (sm != NULL &&
			    sm->sm_dbuf->db_size == sizeof (space_map_phys_t))
				refcount++;
		}
	}
	for (unsigned c = 0; c < vd->vdev_children; c++)
		refcount += get_metaslab_refcount(vd->vdev_child[c]);

	return (refcount);
}

static int
get_obsolete_refcount(vdev_t *vd)
{
	uint64_t obsolete_sm_object;
	int refcount = 0;

	VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
	if (vd->vdev_top == vd && obsolete_sm_object != 0) {
		dmu_object_info_t doi;
		VERIFY0(dmu_object_info(vd->vdev_spa->spa_meta_objset,
		    obsolete_sm_object, &doi));
		if (doi.doi_bonus_size == sizeof (space_map_phys_t)) {
			refcount++;
		}
	} else {
		ASSERT0P(vd->vdev_obsolete_sm);
		ASSERT0(obsolete_sm_object);
	}
	for (unsigned c = 0; c < vd->vdev_children; c++) {
		refcount += get_obsolete_refcount(vd->vdev_child[c]);
	}

	return (refcount);
}

static int
get_prev_obsolete_spacemap_refcount(spa_t *spa)
{
	uint64_t prev_obj =
	    spa->spa_condensing_indirect_phys.scip_prev_obsolete_sm_object;
	if (prev_obj != 0) {
		dmu_object_info_t doi;
		VERIFY0(dmu_object_info(spa->spa_meta_objset, prev_obj, &doi));
		if (doi.doi_bonus_size == sizeof (space_map_phys_t)) {
			return (1);
		}
	}
	return (0);
}

static int
get_checkpoint_refcount(vdev_t *vd)
{
	int refcount = 0;

	if (vd->vdev_top == vd && vd->vdev_top_zap != 0 &&
	    zap_contains(spa_meta_objset(vd->vdev_spa),
	    vd->vdev_top_zap, VDEV_TOP_ZAP_POOL_CHECKPOINT_SM) == 0)
		refcount++;

	for (uint64_t c = 0; c < vd->vdev_children; c++)
		refcount += get_checkpoint_refcount(vd->vdev_child[c]);

	return (refcount);
}

static int
get_log_spacemap_refcount(spa_t *spa)
{
	return (avl_numnodes(&spa->spa_sm_logs_by_txg));
}

static int
verify_spacemap_refcounts(spa_t *spa)
{
	uint64_t expected_refcount = 0;
	uint64_t actual_refcount;

	(void) feature_get_refcount(spa,
	    &spa_feature_table[SPA_FEATURE_SPACEMAP_HISTOGRAM],
	    &expected_refcount);
	actual_refcount = get_dtl_refcount(spa->spa_root_vdev);
	actual_refcount += get_metaslab_refcount(spa->spa_root_vdev);
	actual_refcount += get_obsolete_refcount(spa->spa_root_vdev);
	actual_refcount += get_prev_obsolete_spacemap_refcount(spa);
	actual_refcount += get_checkpoint_refcount(spa->spa_root_vdev);
	actual_refcount += get_log_spacemap_refcount(spa);

	if (expected_refcount != actual_refcount) {
		(void) printf("space map refcount mismatch: expected %lld != "
		    "actual %lld\n",
		    (longlong_t)expected_refcount,
		    (longlong_t)actual_refcount);
		return (2);
	}
	return (0);
}

static void
dump_spacemap(objset_t *os, space_map_t *sm)
{
	const char *ddata[] = { "ALLOC", "FREE", "CONDENSE", "INVALID",
	    "INVALID", "INVALID", "INVALID", "INVALID" };

	if (sm == NULL)
		return;

	(void) printf("space map object %llu:\n",
	    (longlong_t)sm->sm_object);
	(void) printf("  smp_length = 0x%llx\n",
	    (longlong_t)sm->sm_phys->smp_length);
	(void) printf("  smp_alloc = 0x%llx\n",
	    (longlong_t)sm->sm_phys->smp_alloc);

	if (dump_opt['d'] < 6 && dump_opt['m'] < 4)
		return;

	/*
	 * Print out the freelist entries in both encoded and decoded form.
	 */
	uint8_t mapshift = sm->sm_shift;
	int64_t alloc = 0;
	uint64_t word, entry_id = 0;
	for (uint64_t offset = 0; offset < space_map_length(sm);
	    offset += sizeof (word)) {

		VERIFY0(dmu_read(os, space_map_object(sm), offset,
		    sizeof (word), &word, DMU_READ_PREFETCH));

		if (sm_entry_is_debug(word)) {
			uint64_t de_txg = SM_DEBUG_TXG_DECODE(word);
			uint64_t de_sync_pass = SM_DEBUG_SYNCPASS_DECODE(word);
			if (de_txg == 0) {
				(void) printf(
				    "\t    [%6llu] PADDING\n",
				    (u_longlong_t)entry_id);
			} else {
				(void) printf(
				    "\t    [%6llu] %s: txg %llu pass %llu\n",
				    (u_longlong_t)entry_id,
				    ddata[SM_DEBUG_ACTION_DECODE(word)],
				    (u_longlong_t)de_txg,
				    (u_longlong_t)de_sync_pass);
			}
			entry_id++;
			continue;
		}

		char entry_type;
		uint64_t entry_off, entry_run, entry_vdev;

		if (sm_entry_is_single_word(word)) {
			entry_type = (SM_TYPE_DECODE(word) == SM_ALLOC) ?
			    'A' : 'F';
			entry_off = (SM_OFFSET_DECODE(word) << mapshift) +
			    sm->sm_start;
			entry_run = SM_RUN_DECODE(word) << mapshift;

			(void) printf("\t    [%6llu] %c "
			    "range: %012llx-%012llx size: %08llx\n",
			    (u_longlong_t)entry_id, entry_type,
			    (u_longlong_t)entry_off,
			    (u_longlong_t)(entry_off + entry_run - 1),
			    (u_longlong_t)entry_run);
		} else {
			/* it is a two-word entry so we read another word */
			ASSERT(sm_entry_is_double_word(word));

			uint64_t extra_word;
			offset += sizeof (extra_word);
			ASSERT3U(offset, <, space_map_length(sm));
			VERIFY0(dmu_read(os, space_map_object(sm), offset,
			    sizeof (extra_word), &extra_word,
			    DMU_READ_PREFETCH));

			entry_run = SM2_RUN_DECODE(word) << mapshift;
			entry_vdev = SM2_VDEV_DECODE(word);
			entry_type = (SM2_TYPE_DECODE(extra_word) == SM_ALLOC) ?
			    'A' : 'F';
			entry_off = (SM2_OFFSET_DECODE(extra_word) <<
			    mapshift) + sm->sm_start;

			if (zopt_metaslab_args == 0 ||
			    zopt_metaslab[0] == entry_vdev) {
				(void) printf("\t    [%6llu] %c "
				    "range: %012llx-%012llx size: %08llx "
				    "vdev: %llu\n",
				    (u_longlong_t)entry_id, entry_type,
				    (u_longlong_t)entry_off,
				    (u_longlong_t)(entry_off + entry_run - 1),
				    (u_longlong_t)entry_run,
				    (u_longlong_t)entry_vdev);
			}
		}

		if (entry_type == 'A')
			alloc += entry_run;
		else
			alloc -= entry_run;
		entry_id++;
	}
	if (alloc != space_map_allocated(sm)) {
		(void) printf("space_map_object alloc (%lld) INCONSISTENT "
		    "with space map summary (%lld)\n",
		    (longlong_t)space_map_allocated(sm), (longlong_t)alloc);
	}
}

static void
dump_metaslab_stats(metaslab_t *msp)
{
	char maxbuf[32];
	zfs_range_tree_t *rt = msp->ms_allocatable;
	zfs_btree_t *t = &msp->ms_allocatable_by_size;
	int free_pct = zfs_range_tree_space(rt) * 100 / msp->ms_size;

	/* max sure nicenum has enough space */
	_Static_assert(sizeof (maxbuf) >= NN_NUMBUF_SZ, "maxbuf truncated");

	zdb_nicenum(metaslab_largest_allocatable(msp), maxbuf, sizeof (maxbuf));

	(void) printf("\t %25s %10lu   %7s  %6s   %4s %4d%%\n",
	    "segments", zfs_btree_numnodes(t), "maxsize", maxbuf,
	    "freepct", free_pct);
	(void) printf("\tIn-memory histogram:\n");
	dump_histogram(rt->rt_histogram, ZFS_RANGE_TREE_HISTOGRAM_SIZE, 0);
}

static void
dump_allocated(void *arg, uint64_t start, uint64_t size)
{
	uint64_t *off = arg;
	if (*off != start)
		(void) printf("ALLOC: %"PRIu64" %"PRIu64"\n", *off,
		    start - *off);
	*off = start + size;
}

static void
dump_metaslab(metaslab_t *msp)
{
	vdev_t *vd = msp->ms_group->mg_vd;
	spa_t *spa = vd->vdev_spa;
	space_map_t *sm = msp->ms_sm;
	char freebuf[32];

	zdb_nicenum(msp->ms_size - space_map_allocated(sm), freebuf,
	    sizeof (freebuf));

	(void) printf(
	    "\tmetaslab %6llu   offset %12llx   spacemap %6llu   free    %5s\n",
	    (u_longlong_t)msp->ms_id, (u_longlong_t)msp->ms_start,
	    (u_longlong_t)space_map_object(sm), freebuf);

	if (dump_opt[ALLOCATED_OPT] ||
	    (dump_opt['m'] > 2 && !dump_opt['L'])) {
		mutex_enter(&msp->ms_lock);
		VERIFY0(metaslab_load(msp));
	}

	if (dump_opt['m'] > 2 && !dump_opt['L']) {
		zfs_range_tree_stat_verify(msp->ms_allocatable);
		dump_metaslab_stats(msp);
	}

	if (dump_opt[ALLOCATED_OPT]) {
		uint64_t off = msp->ms_start;
		zfs_range_tree_walk(msp->ms_allocatable, dump_allocated,
		    &off);
		if (off != msp->ms_start + msp->ms_size)
			(void) printf("ALLOC: %"PRIu64" %"PRIu64"\n", off,
			    msp->ms_size - off);
	}

	if (dump_opt['m'] > 1 && sm != NULL &&
	    spa_feature_is_active(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM)) {
		/*
		 * The space map histogram represents free space in chunks
		 * of sm_shift (i.e. bucket 0 refers to 2^sm_shift).
		 */
		(void) printf("\tOn-disk histogram:\t\tfragmentation %llu\n",
		    (u_longlong_t)msp->ms_fragmentation);
		dump_histogram(sm->sm_phys->smp_histogram,
		    SPACE_MAP_HISTOGRAM_SIZE, sm->sm_shift);
	}

	if (dump_opt[ALLOCATED_OPT] ||
	    (dump_opt['m'] > 2 && !dump_opt['L'])) {
		metaslab_unload(msp);
		mutex_exit(&msp->ms_lock);
	}

	if (vd->vdev_ops == &vdev_draid_ops)
		ASSERT3U(msp->ms_size, <=, 1ULL << vd->vdev_ms_shift);
	else
		ASSERT3U(msp->ms_size, ==, 1ULL << vd->vdev_ms_shift);

	dump_spacemap(spa->spa_meta_objset, msp->ms_sm);

	if (spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP)) {
		(void) printf("\tFlush data:\n\tunflushed txg=%llu\n\n",
		    (u_longlong_t)metaslab_unflushed_txg(msp));
	}
}

static void
print_vdev_metaslab_header(vdev_t *vd)
{
	vdev_alloc_bias_t alloc_bias = vd->vdev_alloc_bias;
	const char *bias_str = "";
	if (alloc_bias == VDEV_BIAS_LOG || vd->vdev_islog) {
		bias_str = VDEV_ALLOC_BIAS_LOG;
	} else if (alloc_bias == VDEV_BIAS_SPECIAL) {
		bias_str = VDEV_ALLOC_BIAS_SPECIAL;
	} else if (alloc_bias == VDEV_BIAS_DEDUP) {
		bias_str = VDEV_ALLOC_BIAS_DEDUP;
	}

	uint64_t ms_flush_data_obj = 0;
	if (vd->vdev_top_zap != 0) {
		int error = zap_lookup(spa_meta_objset(vd->vdev_spa),
		    vd->vdev_top_zap, VDEV_TOP_ZAP_MS_UNFLUSHED_PHYS_TXGS,
		    sizeof (uint64_t), 1, &ms_flush_data_obj);
		if (error != ENOENT) {
			ASSERT0(error);
		}
	}

	(void) printf("\tvdev %10llu\t%s  metaslab shift %4llu",
	    (u_longlong_t)vd->vdev_id, bias_str,
	    (u_longlong_t)vd->vdev_ms_shift);

	if (ms_flush_data_obj != 0) {
		(void) printf("   ms_unflushed_phys object %llu",
		    (u_longlong_t)ms_flush_data_obj);
	}

	(void) printf("\n\t%-10s%5llu   %-19s   %-15s   %-12s\n",
	    "metaslabs", (u_longlong_t)vd->vdev_ms_count,
	    "offset", "spacemap", "free");
	(void) printf("\t%15s   %19s   %15s   %12s\n",
	    "---------------", "-------------------",
	    "---------------", "------------");
}

static void
dump_metaslab_groups(spa_t *spa, boolean_t show_special)
{
	vdev_t *rvd = spa->spa_root_vdev;
	metaslab_class_t *mc = spa_normal_class(spa);
	metaslab_class_t *smc = spa_special_class(spa);
	uint64_t fragmentation;

	metaslab_class_histogram_verify(mc);

	for (unsigned c = 0; c < rvd->vdev_children; c++) {
		vdev_t *tvd = rvd->vdev_child[c];
		metaslab_group_t *mg = tvd->vdev_mg;

		if (mg == NULL || (mg->mg_class != mc &&
		    (!show_special || mg->mg_class != smc)))
			continue;

		metaslab_group_histogram_verify(mg);
		mg->mg_fragmentation = metaslab_group_fragmentation(mg);

		(void) printf("\tvdev %10llu\t\tmetaslabs%5llu\t\t"
		    "fragmentation",
		    (u_longlong_t)tvd->vdev_id,
		    (u_longlong_t)tvd->vdev_ms_count);
		if (mg->mg_fragmentation == ZFS_FRAG_INVALID) {
			(void) printf("%3s\n", "-");
		} else {
			(void) printf("%3llu%%\n",
			    (u_longlong_t)mg->mg_fragmentation);
		}
		dump_histogram(mg->mg_histogram,
		    ZFS_RANGE_TREE_HISTOGRAM_SIZE, 0);
	}

	(void) printf("\tpool %s\tfragmentation", spa_name(spa));
	fragmentation = metaslab_class_fragmentation(mc);
	if (fragmentation == ZFS_FRAG_INVALID)
		(void) printf("\t%3s\n", "-");
	else
		(void) printf("\t%3llu%%\n", (u_longlong_t)fragmentation);
	dump_histogram(mc->mc_histogram, ZFS_RANGE_TREE_HISTOGRAM_SIZE, 0);
}

static void
print_vdev_indirect(vdev_t *vd)
{
	vdev_indirect_config_t *vic = &vd->vdev_indirect_config;
	vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;
	vdev_indirect_births_t *vib = vd->vdev_indirect_births;

	if (vim == NULL) {
		ASSERT0P(vib);
		return;
	}

	ASSERT3U(vdev_indirect_mapping_object(vim), ==,
	    vic->vic_mapping_object);
	ASSERT3U(vdev_indirect_births_object(vib), ==,
	    vic->vic_births_object);

	(void) printf("indirect births obj %llu:\n",
	    (longlong_t)vic->vic_births_object);
	(void) printf("    vib_count = %llu\n",
	    (longlong_t)vdev_indirect_births_count(vib));
	for (uint64_t i = 0; i < vdev_indirect_births_count(vib); i++) {
		vdev_indirect_birth_entry_phys_t *cur_vibe =
		    &vib->vib_entries[i];
		(void) printf("\toffset %llx -> txg %llu\n",
		    (longlong_t)cur_vibe->vibe_offset,
		    (longlong_t)cur_vibe->vibe_phys_birth_txg);
	}
	(void) printf("\n");

	(void) printf("indirect mapping obj %llu:\n",
	    (longlong_t)vic->vic_mapping_object);
	(void) printf("    vim_max_offset = 0x%llx\n",
	    (longlong_t)vdev_indirect_mapping_max_offset(vim));
	(void) printf("    vim_bytes_mapped = 0x%llx\n",
	    (longlong_t)vdev_indirect_mapping_bytes_mapped(vim));
	(void) printf("    vim_count = %llu\n",
	    (longlong_t)vdev_indirect_mapping_num_entries(vim));

	if (dump_opt['d'] <= 5 && dump_opt['m'] <= 3)
		return;

	uint32_t *counts = vdev_indirect_mapping_load_obsolete_counts(vim);

	for (uint64_t i = 0; i < vdev_indirect_mapping_num_entries(vim); i++) {
		vdev_indirect_mapping_entry_phys_t *vimep =
		    &vim->vim_entries[i];
		(void) printf("\t<%llx:%llx:%llx> -> "
		    "<%llx:%llx:%llx> (%x obsolete)\n",
		    (longlong_t)vd->vdev_id,
		    (longlong_t)DVA_MAPPING_GET_SRC_OFFSET(vimep),
		    (longlong_t)DVA_GET_ASIZE(&vimep->vimep_dst),
		    (longlong_t)DVA_GET_VDEV(&vimep->vimep_dst),
		    (longlong_t)DVA_GET_OFFSET(&vimep->vimep_dst),
		    (longlong_t)DVA_GET_ASIZE(&vimep->vimep_dst),
		    counts[i]);
	}
	(void) printf("\n");

	uint64_t obsolete_sm_object;
	VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
	if (obsolete_sm_object != 0) {
		objset_t *mos = vd->vdev_spa->spa_meta_objset;
		(void) printf("obsolete space map object %llu:\n",
		    (u_longlong_t)obsolete_sm_object);
		ASSERT(vd->vdev_obsolete_sm != NULL);
		ASSERT3U(space_map_object(vd->vdev_obsolete_sm), ==,
		    obsolete_sm_object);
		dump_spacemap(mos, vd->vdev_obsolete_sm);
		(void) printf("\n");
	}
}

static void
dump_metaslabs(spa_t *spa)
{
	vdev_t *vd, *rvd = spa->spa_root_vdev;
	uint64_t m, c = 0, children = rvd->vdev_children;

	(void) printf("\nMetaslabs:\n");

	if (zopt_metaslab_args > 0) {
		c = zopt_metaslab[0];

		if (c >= children)
			(void) fatal("bad vdev id: %llu", (u_longlong_t)c);

		if (zopt_metaslab_args > 1) {
			vd = rvd->vdev_child[c];
			print_vdev_metaslab_header(vd);

			for (m = 1; m < zopt_metaslab_args; m++) {
				if (zopt_metaslab[m] < vd->vdev_ms_count)
					dump_metaslab(
					    vd->vdev_ms[zopt_metaslab[m]]);
				else
					(void) fprintf(stderr, "bad metaslab "
					    "number %llu\n",
					    (u_longlong_t)zopt_metaslab[m]);
			}
			(void) printf("\n");
			return;
		}
		children = c + 1;
	}
	for (; c < children; c++) {
		vd = rvd->vdev_child[c];
		print_vdev_metaslab_header(vd);

		print_vdev_indirect(vd);

		for (m = 0; m < vd->vdev_ms_count; m++)
			dump_metaslab(vd->vdev_ms[m]);
		(void) printf("\n");
	}
}

static void
dump_log_spacemaps(spa_t *spa)
{
	if (!spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))
		return;

	(void) printf("\nLog Space Maps in Pool:\n");
	for (spa_log_sm_t *sls = avl_first(&spa->spa_sm_logs_by_txg);
	    sls; sls = AVL_NEXT(&spa->spa_sm_logs_by_txg, sls)) {
		space_map_t *sm = NULL;
		VERIFY0(space_map_open(&sm, spa_meta_objset(spa),
		    sls->sls_sm_obj, 0, UINT64_MAX, SPA_MINBLOCKSHIFT));

		(void) printf("Log Spacemap object %llu txg %llu\n",
		    (u_longlong_t)sls->sls_sm_obj, (u_longlong_t)sls->sls_txg);
		dump_spacemap(spa->spa_meta_objset, sm);
		space_map_close(sm);
	}
	(void) printf("\n");
}

static void
dump_ddt_entry(const ddt_t *ddt, const ddt_lightweight_entry_t *ddlwe,
    uint64_t index)
{
	const ddt_key_t *ddk = &ddlwe->ddlwe_key;
	char blkbuf[BP_SPRINTF_LEN];
	blkptr_t blk;
	int p;

	for (p = 0; p < DDT_NPHYS(ddt); p++) {
		const ddt_univ_phys_t *ddp = &ddlwe->ddlwe_phys;
		ddt_phys_variant_t v = DDT_PHYS_VARIANT(ddt, p);

		if (ddt_phys_birth(ddp, v) == 0)
			continue;
		ddt_bp_create(ddt->ddt_checksum, ddk, ddp, v, &blk);
		snprintf_blkptr(blkbuf, sizeof (blkbuf), &blk);
		(void) printf("index %llx refcnt %llu phys %d %s\n",
		    (u_longlong_t)index, (u_longlong_t)ddt_phys_refcnt(ddp, v),
		    p, blkbuf);
	}
}

static void
dump_dedup_ratio(const ddt_stat_t *dds)
{
	double rL, rP, rD, D, dedup, compress, copies;

	if (dds->dds_blocks == 0)
		return;

	rL = (double)dds->dds_ref_lsize;
	rP = (double)dds->dds_ref_psize;
	rD = (double)dds->dds_ref_dsize;
	D = (double)dds->dds_dsize;

	dedup = rD / D;
	compress = rL / rP;
	copies = rD / rP;

	(void) printf("dedup = %.2f, compress = %.2f, copies = %.2f, "
	    "dedup * compress / copies = %.2f\n\n",
	    dedup, compress, copies, dedup * compress / copies);
}

static void
dump_ddt_log(ddt_t *ddt)
{
	if (ddt->ddt_version != DDT_VERSION_FDT ||
	    !(ddt->ddt_flags & DDT_FLAG_LOG))
		return;

	for (int n = 0; n < 2; n++) {
		ddt_log_t *ddl = &ddt->ddt_log[n];

		char flagstr[64] = {0};
		if (ddl->ddl_flags > 0) {
			flagstr[0] = ' ';
			int c = 1;
			if (ddl->ddl_flags & DDL_FLAG_FLUSHING)
				c += strlcpy(&flagstr[c], " FLUSHING",
				    sizeof (flagstr) - c);
			if (ddl->ddl_flags & DDL_FLAG_CHECKPOINT)
				c += strlcpy(&flagstr[c], " CHECKPOINT",
				    sizeof (flagstr) - c);
			if (ddl->ddl_flags &
			    ~(DDL_FLAG_FLUSHING|DDL_FLAG_CHECKPOINT))
				c += strlcpy(&flagstr[c], " UNKNOWN",
				    sizeof (flagstr) - c);
			flagstr[1] = '[';
			flagstr[c] = ']';
		}

		uint64_t count = avl_numnodes(&ddl->ddl_tree);

		printf(DMU_POOL_DDT_LOG ": flags=0x%02x%s; obj=%llu; "
		    "len=%llu; txg=%llu; entries=%llu\n",
		    zio_checksum_table[ddt->ddt_checksum].ci_name, n,
		    ddl->ddl_flags, flagstr,
		    (u_longlong_t)ddl->ddl_object,
		    (u_longlong_t)ddl->ddl_length,
		    (u_longlong_t)ddl->ddl_first_txg, (u_longlong_t)count);

		if (ddl->ddl_flags & DDL_FLAG_CHECKPOINT) {
			const ddt_key_t *ddk = &ddl->ddl_checkpoint;
			printf("    checkpoint: "
			    "%016llx:%016llx:%016llx:%016llx:%016llx\n",
			    (u_longlong_t)ddk->ddk_cksum.zc_word[0],
			    (u_longlong_t)ddk->ddk_cksum.zc_word[1],
			    (u_longlong_t)ddk->ddk_cksum.zc_word[2],
			    (u_longlong_t)ddk->ddk_cksum.zc_word[3],
			    (u_longlong_t)ddk->ddk_prop);
		}

		if (count == 0 || dump_opt['D'] < 4)
			continue;

		ddt_lightweight_entry_t ddlwe;
		uint64_t index = 0;
		for (ddt_log_entry_t *ddle = avl_first(&ddl->ddl_tree);
		    ddle; ddle = AVL_NEXT(&ddl->ddl_tree, ddle)) {
			DDT_LOG_ENTRY_TO_LIGHTWEIGHT(ddt, ddle, &ddlwe);
			dump_ddt_entry(ddt, &ddlwe, index++);
		}
	}
}

static void
dump_ddt_object(ddt_t *ddt, ddt_type_t type, ddt_class_t class)
{
	char name[DDT_NAMELEN];
	ddt_lightweight_entry_t ddlwe;
	uint64_t walk = 0;
	dmu_object_info_t doi;
	uint64_t count, dspace, mspace;
	int error;

	error = ddt_object_info(ddt, type, class, &doi);

	if (error == ENOENT)
		return;
	ASSERT0(error);

	error = ddt_object_count(ddt, type, class, &count);
	ASSERT0(error);
	if (count == 0)
		return;

	dspace = doi.doi_physical_blocks_512 << 9;
	mspace = doi.doi_fill_count * doi.doi_data_block_size;

	ddt_object_name(ddt, type, class, name);

	(void) printf("%s: dspace=%llu; mspace=%llu; entries=%llu\n", name,
	    (u_longlong_t)dspace, (u_longlong_t)mspace, (u_longlong_t)count);

	if (dump_opt['D'] < 3)
		return;

	(void) printf("%s: object=%llu\n", name,
	    (u_longlong_t)ddt->ddt_object[type][class]);
	zpool_dump_ddt(NULL, &ddt->ddt_histogram[type][class]);

	if (dump_opt['D'] < 4)
		return;

	if (dump_opt['D'] < 5 && class == DDT_CLASS_UNIQUE)
		return;

	(void) printf("%s contents:\n\n", name);

	while ((error = ddt_object_walk(ddt, type, class, &walk, &ddlwe)) == 0)
		dump_ddt_entry(ddt, &ddlwe, walk);

	ASSERT3U(error, ==, ENOENT);

	(void) printf("\n");
}

static void
dump_ddt(ddt_t *ddt)
{
	if (!ddt || ddt->ddt_version == DDT_VERSION_UNCONFIGURED)
		return;

	char flagstr[64] = {0};
	if (ddt->ddt_flags > 0) {
		flagstr[0] = ' ';
		int c = 1;
		if (ddt->ddt_flags & DDT_FLAG_FLAT)
			c += strlcpy(&flagstr[c], " FLAT",
			    sizeof (flagstr) - c);
		if (ddt->ddt_flags & DDT_FLAG_LOG)
			c += strlcpy(&flagstr[c], " LOG",
			    sizeof (flagstr) - c);
		if (ddt->ddt_flags & ~DDT_FLAG_MASK)
			c += strlcpy(&flagstr[c], " UNKNOWN",
			    sizeof (flagstr) - c);
		flagstr[1] = '[';
		flagstr[c] = ']';
	}

	printf("DDT-%s: version=%llu [%s]; flags=0x%02llx%s; rootobj=%llu\n",
	    zio_checksum_table[ddt->ddt_checksum].ci_name,
	    (u_longlong_t)ddt->ddt_version,
	    (ddt->ddt_version == 0) ? "LEGACY" :
	    (ddt->ddt_version == 1) ? "FDT" : "UNKNOWN",
	    (u_longlong_t)ddt->ddt_flags, flagstr,
	    (u_longlong_t)ddt->ddt_dir_object);

	for (ddt_type_t type = 0; type < DDT_TYPES; type++)
		for (ddt_class_t class = 0; class < DDT_CLASSES; class++)
			dump_ddt_object(ddt, type, class);

	dump_ddt_log(ddt);
}

static void
dump_all_ddts(spa_t *spa)
{
	ddt_histogram_t ddh_total = {{{0}}};
	ddt_stat_t dds_total = {0};

	for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++)
		dump_ddt(spa->spa_ddt[c]);

	ddt_get_dedup_stats(spa, &dds_total);

	if (dds_total.dds_blocks == 0) {
		(void) printf("All DDTs are empty\n");
		return;
	}

	(void) printf("\n");

	if (dump_opt['D'] > 1) {
		(void) printf("DDT histogram (aggregated over all DDTs):\n");
		ddt_get_dedup_histogram(spa, &ddh_total);
		zpool_dump_ddt(&dds_total, &ddh_total);
	}

	dump_dedup_ratio(&dds_total);

	/*
	 * Dump a histogram of unique class entry age
	 */
	if (dump_opt['D'] == 3 && getenv("ZDB_DDT_UNIQUE_AGE_HIST") != NULL) {
		ddt_age_histo_t histogram;

		(void) printf("DDT walk unique, building age histogram...\n");
		ddt_prune_walk(spa, 0, &histogram);

		/*
		 * print out histogram for unique entry class birth
		 */
		if (histogram.dah_entries > 0) {
			(void) printf("%5s  %9s  %4s\n",
			    "age", "blocks", "amnt");
			(void) printf("%5s  %9s  %4s\n",
			    "-----", "---------", "----");
			for (int i = 0; i < HIST_BINS; i++) {
				(void) printf("%5d  %9d %4d%%\n", 1 << i,
				    (int)histogram.dah_age_histo[i],
				    (int)((histogram.dah_age_histo[i] * 100) /
				    histogram.dah_entries));
			}
		}
	}
}

static void
dump_brt(spa_t *spa)
{
	if (!spa_feature_is_enabled(spa, SPA_FEATURE_BLOCK_CLONING)) {
		printf("BRT: unsupported on this pool\n");
		return;
	}

	if (!spa_feature_is_active(spa, SPA_FEATURE_BLOCK_CLONING)) {
		printf("BRT: empty\n");
		return;
	}

	char count[32], used[32], saved[32];
	zdb_nicebytes(brt_get_used(spa), used, sizeof (used));
	zdb_nicebytes(brt_get_saved(spa), saved, sizeof (saved));
	uint64_t ratio = brt_get_ratio(spa);
	printf("BRT: used %s; saved %s; ratio %llu.%02llux\n", used, saved,
	    (u_longlong_t)(ratio / 100), (u_longlong_t)(ratio % 100));

	if (dump_opt['T'] < 2)
		return;

	for (uint64_t vdevid = 0; vdevid < spa->spa_brt_nvdevs; vdevid++) {
		brt_vdev_t *brtvd = spa->spa_brt_vdevs[vdevid];
		if (!brtvd->bv_initiated) {
			printf("BRT: vdev %" PRIu64 ": empty\n", vdevid);
			continue;
		}

		zdb_nicenum(brtvd->bv_totalcount, count, sizeof (count));
		zdb_nicebytes(brtvd->bv_usedspace, used, sizeof (used));
		zdb_nicebytes(brtvd->bv_savedspace, saved, sizeof (saved));
		printf("BRT: vdev %" PRIu64 ": refcnt %s; used %s; saved %s\n",
		    vdevid, count, used, saved);
	}

	if (dump_opt['T'] < 3)
		return;

	/* -TTT shows a per-vdev histograms; -TTTT shows all entries */
	boolean_t do_histo = dump_opt['T'] == 3;

	char dva[64];

	if (!do_histo)
		printf("\n%-16s %-10s\n", "DVA", "REFCNT");

	for (uint64_t vdevid = 0; vdevid < spa->spa_brt_nvdevs; vdevid++) {
		brt_vdev_t *brtvd = spa->spa_brt_vdevs[vdevid];
		if (!brtvd->bv_initiated)
			continue;

		uint64_t counts[64] = {};

		zap_cursor_t zc;
		zap_attribute_t *za = zap_attribute_alloc();
		for (zap_cursor_init(&zc, spa->spa_meta_objset,
		    brtvd->bv_mos_entries);
		    zap_cursor_retrieve(&zc, za) == 0;
		    zap_cursor_advance(&zc)) {
			uint64_t refcnt;
			VERIFY0(zap_lookup_uint64(spa->spa_meta_objset,
			    brtvd->bv_mos_entries,
			    (const uint64_t *)za->za_name, 1,
			    za->za_integer_length, za->za_num_integers,
			    &refcnt));

			if (do_histo)
				counts[highbit64(refcnt)]++;
			else {
				uint64_t offset =
				    *(const uint64_t *)za->za_name;

				snprintf(dva, sizeof (dva), "%" PRIu64 ":%llx",
				    vdevid, (u_longlong_t)offset);
				printf("%-16s %-10llu\n", dva,
				    (u_longlong_t)refcnt);
			}
		}
		zap_cursor_fini(&zc);
		zap_attribute_free(za);

		if (do_histo) {
			printf("\nBRT: vdev %" PRIu64
			    ": DVAs with 2^n refcnts:\n", vdevid);
			dump_histogram(counts, 64, 0);
		}
	}
}

static void
dump_dtl_seg(void *arg, uint64_t start, uint64_t size)
{
	char *prefix = arg;

	(void) printf("%s [%llu,%llu) length %llu\n",
	    prefix,
	    (u_longlong_t)start,
	    (u_longlong_t)(start + size),
	    (u_longlong_t)(size));
}

static void
dump_dtl(vdev_t *vd, int indent)
{
	spa_t *spa = vd->vdev_spa;
	boolean_t required;
	const char *name[DTL_TYPES] = { "missing", "partial", "scrub",
		"outage" };
	char prefix[256];

	spa_vdev_state_enter(spa, SCL_NONE);
	required = vdev_dtl_required(vd);
	(void) spa_vdev_state_exit(spa, NULL, 0);

	if (indent == 0)
		(void) printf("\nDirty time logs:\n\n");

	(void) printf("\t%*s%s [%s]\n", indent, "",
	    vd->vdev_path ? vd->vdev_path :
	    vd->vdev_parent ? vd->vdev_ops->vdev_op_type : spa_name(spa),
	    required ? "DTL-required" : "DTL-expendable");

	for (int t = 0; t < DTL_TYPES; t++) {
		zfs_range_tree_t *rt = vd->vdev_dtl[t];
		if (zfs_range_tree_space(rt) == 0)
			continue;
		(void) snprintf(prefix, sizeof (prefix), "\t%*s%s",
		    indent + 2, "", name[t]);
		zfs_range_tree_walk(rt, dump_dtl_seg, prefix);
		if (dump_opt['d'] > 5 && vd->vdev_children == 0)
			dump_spacemap(spa->spa_meta_objset,
			    vd->vdev_dtl_sm);
	}

	for (unsigned c = 0; c < vd->vdev_children; c++)
		dump_dtl(vd->vdev_child[c], indent + 4);
}

static void
dump_history(spa_t *spa)
{
	nvlist_t **events = NULL;
	char *buf;
	uint64_t resid, len, off = 0;
	uint_t num = 0;
	int error;
	char tbuf[30];

	if ((buf = malloc(SPA_OLD_MAXBLOCKSIZE)) == NULL) {
		(void) fprintf(stderr, "%s: unable to allocate I/O buffer\n",
		    __func__);
		return;
	}

	do {
		len = SPA_OLD_MAXBLOCKSIZE;

		if ((error = spa_history_get(spa, &off, &len, buf)) != 0) {
			(void) fprintf(stderr, "Unable to read history: "
			    "error %d\n", error);
			free(buf);
			return;
		}

		if (zpool_history_unpack(buf, len, &resid, &events, &num) != 0)
			break;

		off -= resid;
	} while (len != 0);

	(void) printf("\nHistory:\n");
	for (unsigned i = 0; i < num; i++) {
		boolean_t printed = B_FALSE;

		if (nvlist_exists(events[i], ZPOOL_HIST_TIME)) {
			time_t tsec;
			struct tm t;

			tsec = fnvlist_lookup_uint64(events[i],
			    ZPOOL_HIST_TIME);
			(void) localtime_r(&tsec, &t);
			(void) strftime(tbuf, sizeof (tbuf), "%F.%T", &t);
		} else {
			tbuf[0] = '\0';
		}

		if (nvlist_exists(events[i], ZPOOL_HIST_CMD)) {
			(void) printf("%s %s\n", tbuf,
			    fnvlist_lookup_string(events[i], ZPOOL_HIST_CMD));
		} else if (nvlist_exists(events[i], ZPOOL_HIST_INT_EVENT)) {
			uint64_t ievent;

			ievent = fnvlist_lookup_uint64(events[i],
			    ZPOOL_HIST_INT_EVENT);
			if (ievent >= ZFS_NUM_LEGACY_HISTORY_EVENTS)
				goto next;

			(void) printf(" %s [internal %s txg:%ju] %s\n",
			    tbuf,
			    zfs_history_event_names[ievent],
			    fnvlist_lookup_uint64(events[i],
			    ZPOOL_HIST_TXG),
			    fnvlist_lookup_string(events[i],
			    ZPOOL_HIST_INT_STR));
		} else if (nvlist_exists(events[i], ZPOOL_HIST_INT_NAME)) {
			(void) printf("%s [txg:%ju] %s", tbuf,
			    fnvlist_lookup_uint64(events[i],
			    ZPOOL_HIST_TXG),
			    fnvlist_lookup_string(events[i],
			    ZPOOL_HIST_INT_NAME));

			if (nvlist_exists(events[i], ZPOOL_HIST_DSNAME)) {
				(void) printf(" %s (%llu)",
				    fnvlist_lookup_string(events[i],
				    ZPOOL_HIST_DSNAME),
				    (u_longlong_t)fnvlist_lookup_uint64(
				    events[i],
				    ZPOOL_HIST_DSID));
			}

			(void) printf(" %s\n", fnvlist_lookup_string(events[i],
			    ZPOOL_HIST_INT_STR));
		} else if (nvlist_exists(events[i], ZPOOL_HIST_IOCTL)) {
			(void) printf("%s ioctl %s\n", tbuf,
			    fnvlist_lookup_string(events[i],
			    ZPOOL_HIST_IOCTL));

			if (nvlist_exists(events[i], ZPOOL_HIST_INPUT_NVL)) {
				(void) printf("    input:\n");
				dump_nvlist(fnvlist_lookup_nvlist(events[i],
				    ZPOOL_HIST_INPUT_NVL), 8);
			}
			if (nvlist_exists(events[i], ZPOOL_HIST_OUTPUT_NVL)) {
				(void) printf("    output:\n");
				dump_nvlist(fnvlist_lookup_nvlist(events[i],
				    ZPOOL_HIST_OUTPUT_NVL), 8);
			}
			if (nvlist_exists(events[i], ZPOOL_HIST_ERRNO)) {
				(void) printf("    errno: %lld\n",
				    (longlong_t)fnvlist_lookup_int64(events[i],
				    ZPOOL_HIST_ERRNO));
			}
		} else {
			goto next;
		}

		printed = B_TRUE;
next:
		if (dump_opt['h'] > 1) {
			if (!printed)
				(void) printf("unrecognized record:\n");
			dump_nvlist(events[i], 2);
		}
	}
	free(buf);
}

static void
dump_dnode(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) data, (void) size;
}

static uint64_t
blkid2offset(const dnode_phys_t *dnp, const blkptr_t *bp,
    const zbookmark_phys_t *zb)
{
	if (dnp == NULL) {
		ASSERT(zb->zb_level < 0);
		if (zb->zb_object == 0)
			return (zb->zb_blkid);
		return (zb->zb_blkid * BP_GET_LSIZE(bp));
	}

	ASSERT(zb->zb_level >= 0);

	return ((zb->zb_blkid <<
	    (zb->zb_level * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT))) *
	    dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
}

static void
snprintf_zstd_header(spa_t *spa, char *blkbuf, size_t buflen,
    const blkptr_t *bp)
{
	static abd_t *pabd = NULL;
	void *buf;
	zio_t *zio;
	zfs_zstdhdr_t zstd_hdr;
	int error;

	if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_ZSTD)
		return;

	if (BP_IS_HOLE(bp))
		return;

	if (BP_IS_EMBEDDED(bp)) {
		buf = malloc(SPA_MAXBLOCKSIZE);
		if (buf == NULL) {
			(void) fprintf(stderr, "out of memory\n");
			zdb_exit(1);
		}
		decode_embedded_bp_compressed(bp, buf);
		memcpy(&zstd_hdr, buf, sizeof (zstd_hdr));
		free(buf);
		zstd_hdr.c_len = BE_32(zstd_hdr.c_len);
		zstd_hdr.raw_version_level = BE_32(zstd_hdr.raw_version_level);
		(void) snprintf(blkbuf + strlen(blkbuf),
		    buflen - strlen(blkbuf),
		    " ZSTD:size=%u:version=%u:level=%u:EMBEDDED",
		    zstd_hdr.c_len, zfs_get_hdrversion(&zstd_hdr),
		    zfs_get_hdrlevel(&zstd_hdr));
		return;
	}

	if (!pabd)
		pabd = abd_alloc_for_io(SPA_MAXBLOCKSIZE, B_FALSE);
	zio = zio_root(spa, NULL, NULL, 0);

	/* Decrypt but don't decompress so we can read the compression header */
	zio_nowait(zio_read(zio, spa, bp, pabd, BP_GET_PSIZE(bp), NULL, NULL,
	    ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW_COMPRESS,
	    NULL));
	error = zio_wait(zio);
	if (error) {
		(void) fprintf(stderr, "read failed: %d\n", error);
		return;
	}
	buf = abd_borrow_buf_copy(pabd, BP_GET_LSIZE(bp));
	memcpy(&zstd_hdr, buf, sizeof (zstd_hdr));
	zstd_hdr.c_len = BE_32(zstd_hdr.c_len);
	zstd_hdr.raw_version_level = BE_32(zstd_hdr.raw_version_level);

	(void) snprintf(blkbuf + strlen(blkbuf),
	    buflen - strlen(blkbuf),
	    " ZSTD:size=%u:version=%u:level=%u:NORMAL",
	    zstd_hdr.c_len, zfs_get_hdrversion(&zstd_hdr),
	    zfs_get_hdrlevel(&zstd_hdr));

	abd_return_buf_copy(pabd, buf, BP_GET_LSIZE(bp));
}

static void
snprintf_blkptr_compact(char *blkbuf, size_t buflen, const blkptr_t *bp,
    boolean_t bp_freed)
{
	const dva_t *dva = bp->blk_dva;
	int ndvas = dump_opt['d'] > 5 ? BP_GET_NDVAS(bp) : 1;
	int i;

	if (dump_opt['b'] >= 6) {
		snprintf_blkptr(blkbuf, buflen, bp);
		if (bp_freed) {
			(void) snprintf(blkbuf + strlen(blkbuf),
			    buflen - strlen(blkbuf), " %s", "FREE");
		}
		return;
	}

	if (BP_IS_EMBEDDED(bp)) {
		(void) sprintf(blkbuf,
		    "EMBEDDED et=%u %llxL/%llxP B=%llu",
		    (int)BPE_GET_ETYPE(bp),
		    (u_longlong_t)BPE_GET_LSIZE(bp),
		    (u_longlong_t)BPE_GET_PSIZE(bp),
		    (u_longlong_t)BP_GET_LOGICAL_BIRTH(bp));
		return;
	}

	blkbuf[0] = '\0';

	for (i = 0; i < ndvas; i++) {
		(void) snprintf(blkbuf + strlen(blkbuf),
		    buflen - strlen(blkbuf), "%llu:%llx:%llx%s ",
		    (u_longlong_t)DVA_GET_VDEV(&dva[i]),
		    (u_longlong_t)DVA_GET_OFFSET(&dva[i]),
		    (u_longlong_t)DVA_GET_ASIZE(&dva[i]),
		    (DVA_GET_GANG(&dva[i]) ? "G" : ""));
	}

	if (BP_IS_HOLE(bp)) {
		(void) snprintf(blkbuf + strlen(blkbuf),
		    buflen - strlen(blkbuf),
		    "%llxL B=%llu",
		    (u_longlong_t)BP_GET_LSIZE(bp),
		    (u_longlong_t)BP_GET_LOGICAL_BIRTH(bp));
	} else {
		(void) snprintf(blkbuf + strlen(blkbuf),
		    buflen - strlen(blkbuf),
		    "%llxL/%llxP F=%llu B=%llu/%llu",
		    (u_longlong_t)BP_GET_LSIZE(bp),
		    (u_longlong_t)BP_GET_PSIZE(bp),
		    (u_longlong_t)BP_GET_FILL(bp),
		    (u_longlong_t)BP_GET_LOGICAL_BIRTH(bp),
		    (u_longlong_t)BP_GET_PHYSICAL_BIRTH(bp));
		if (bp_freed)
			(void) snprintf(blkbuf + strlen(blkbuf),
			    buflen - strlen(blkbuf), " %s", "FREE");
		(void) snprintf(blkbuf + strlen(blkbuf),
		    buflen - strlen(blkbuf),
		    " cksum=%016llx:%016llx:%016llx:%016llx",
		    (u_longlong_t)bp->blk_cksum.zc_word[0],
		    (u_longlong_t)bp->blk_cksum.zc_word[1],
		    (u_longlong_t)bp->blk_cksum.zc_word[2],
		    (u_longlong_t)bp->blk_cksum.zc_word[3]);
	}
}

static u_longlong_t
print_indirect(spa_t *spa, blkptr_t *bp, const zbookmark_phys_t *zb,
    const dnode_phys_t *dnp)
{
	char blkbuf[BP_SPRINTF_LEN];
	u_longlong_t offset;
	int l;

	offset = (u_longlong_t)blkid2offset(dnp, bp, zb);

	(void) printf("%16llx ", offset);

	ASSERT(zb->zb_level >= 0);

	for (l = dnp->dn_nlevels - 1; l >= -1; l--) {
		if (l == zb->zb_level) {
			(void) printf("L%llx", (u_longlong_t)zb->zb_level);
		} else {
			(void) printf(" ");
		}
	}

	snprintf_blkptr_compact(blkbuf, sizeof (blkbuf), bp, B_FALSE);
	if (dump_opt['Z'] && BP_GET_COMPRESS(bp) == ZIO_COMPRESS_ZSTD)
		snprintf_zstd_header(spa, blkbuf, sizeof (blkbuf), bp);
	(void) printf("%s", blkbuf);

	if (!BP_IS_EMBEDDED(bp)) {
		if (BP_GET_TYPE(bp) != dnp->dn_type) {
			(void) printf(" (ERROR: Block pointer type "
			    "(%llu) does not match dnode type (%hhu))",
			    BP_GET_TYPE(bp), dnp->dn_type);
			corruption_found = B_TRUE;
		}
		if (BP_GET_LEVEL(bp) != zb->zb_level) {
			(void) printf(" (ERROR: Block pointer level "
			    "(%llu) does not match bookmark level (%lld))",
			    BP_GET_LEVEL(bp), (longlong_t)zb->zb_level);
			corruption_found = B_TRUE;
		}
	}
	(void) printf("\n");

	return (offset);
}

static int
visit_indirect(spa_t *spa, const dnode_phys_t *dnp,
    blkptr_t *bp, const zbookmark_phys_t *zb)
{
	u_longlong_t offset;
	int err = 0;

	if (BP_GET_BIRTH(bp) == 0)
		return (0);

	offset = print_indirect(spa, bp, zb, dnp);

	if (BP_GET_LEVEL(bp) > 0 && !BP_IS_HOLE(bp)) {
		arc_flags_t flags = ARC_FLAG_WAIT;
		int i;
		blkptr_t *cbp;
		int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
		arc_buf_t *buf;
		uint64_t fill = 0;
		ASSERT(!BP_IS_REDACTED(bp));

		err = arc_read(NULL, spa, bp, arc_getbuf_func, &buf,
		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
		if (err)
			return (err);
		ASSERT(buf->b_data);

		/* recursively visit blocks below this */
		cbp = buf->b_data;
		for (i = 0; i < epb; i++, cbp++) {
			zbookmark_phys_t czb;

			SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
			    zb->zb_level - 1,
			    zb->zb_blkid * epb + i);
			err = visit_indirect(spa, dnp, cbp, &czb);
			if (err)
				break;
			fill += BP_GET_FILL(cbp);
		}
		if (!err) {
			if (fill != BP_GET_FILL(bp)) {
				(void) printf("%16llx: Block pointer "
				    "fill (%llu) does not match calculated "
				    "value (%llu)\n", offset, BP_GET_FILL(bp),
				    (u_longlong_t)fill);
				corruption_found = B_TRUE;
			}
		}
		arc_buf_destroy(buf, &buf);
	}

	return (err);
}

static void
dump_indirect(dnode_t *dn)
{
	dnode_phys_t *dnp = dn->dn_phys;
	zbookmark_phys_t czb;

	(void) printf("Indirect blocks:\n");

	SET_BOOKMARK(&czb, dmu_objset_id(dn->dn_objset),
	    dn->dn_object, dnp->dn_nlevels - 1, 0);
	for (int j = 0; j < dnp->dn_nblkptr; j++) {
		czb.zb_blkid = j;
		(void) visit_indirect(dmu_objset_spa(dn->dn_objset), dnp,
		    &dnp->dn_blkptr[j], &czb);
	}

	(void) printf("\n");
}

static void
dump_dsl_dir(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object;
	dsl_dir_phys_t *dd = data;
	time_t crtime;
	char nice[32];

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (nice) >= NN_NUMBUF_SZ, "nice truncated");

	if (dd == NULL)
		return;

	ASSERT3U(size, >=, sizeof (dsl_dir_phys_t));

	crtime = dd->dd_creation_time;
	(void) printf("\t\tcreation_time = %s", ctime(&crtime));
	(void) printf("\t\thead_dataset_obj = %llu\n",
	    (u_longlong_t)dd->dd_head_dataset_obj);
	(void) printf("\t\tparent_dir_obj = %llu\n",
	    (u_longlong_t)dd->dd_parent_obj);
	(void) printf("\t\torigin_obj = %llu\n",
	    (u_longlong_t)dd->dd_origin_obj);
	(void) printf("\t\tchild_dir_zapobj = %llu\n",
	    (u_longlong_t)dd->dd_child_dir_zapobj);
	zdb_nicenum(dd->dd_used_bytes, nice, sizeof (nice));
	(void) printf("\t\tused_bytes = %s\n", nice);
	zdb_nicenum(dd->dd_compressed_bytes, nice, sizeof (nice));
	(void) printf("\t\tcompressed_bytes = %s\n", nice);
	zdb_nicenum(dd->dd_uncompressed_bytes, nice, sizeof (nice));
	(void) printf("\t\tuncompressed_bytes = %s\n", nice);
	zdb_nicenum(dd->dd_quota, nice, sizeof (nice));
	(void) printf("\t\tquota = %s\n", nice);
	zdb_nicenum(dd->dd_reserved, nice, sizeof (nice));
	(void) printf("\t\treserved = %s\n", nice);
	(void) printf("\t\tprops_zapobj = %llu\n",
	    (u_longlong_t)dd->dd_props_zapobj);
	(void) printf("\t\tdeleg_zapobj = %llu\n",
	    (u_longlong_t)dd->dd_deleg_zapobj);
	(void) printf("\t\tflags = %llx\n",
	    (u_longlong_t)dd->dd_flags);

#define	DO(which) \
	zdb_nicenum(dd->dd_used_breakdown[DD_USED_ ## which], nice, \
	    sizeof (nice)); \
	(void) printf("\t\tused_breakdown[" #which "] = %s\n", nice)
	DO(HEAD);
	DO(SNAP);
	DO(CHILD);
	DO(CHILD_RSRV);
	DO(REFRSRV);
#undef DO
	(void) printf("\t\tclones = %llu\n",
	    (u_longlong_t)dd->dd_clones);
}

static void
dump_dsl_dataset(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object;
	dsl_dataset_phys_t *ds = data;
	time_t crtime;
	char used[32], compressed[32], uncompressed[32], unique[32];
	char blkbuf[BP_SPRINTF_LEN];

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (used) >= NN_NUMBUF_SZ, "used truncated");
	_Static_assert(sizeof (compressed) >= NN_NUMBUF_SZ,
	    "compressed truncated");
	_Static_assert(sizeof (uncompressed) >= NN_NUMBUF_SZ,
	    "uncompressed truncated");
	_Static_assert(sizeof (unique) >= NN_NUMBUF_SZ, "unique truncated");

	if (ds == NULL)
		return;

	ASSERT(size == sizeof (*ds));
	crtime = ds->ds_creation_time;
	zdb_nicenum(ds->ds_referenced_bytes, used, sizeof (used));
	zdb_nicenum(ds->ds_compressed_bytes, compressed, sizeof (compressed));
	zdb_nicenum(ds->ds_uncompressed_bytes, uncompressed,
	    sizeof (uncompressed));
	zdb_nicenum(ds->ds_unique_bytes, unique, sizeof (unique));
	snprintf_blkptr(blkbuf, sizeof (blkbuf), &ds->ds_bp);

	(void) printf("\t\tdir_obj = %llu\n",
	    (u_longlong_t)ds->ds_dir_obj);
	(void) printf("\t\tprev_snap_obj = %llu\n",
	    (u_longlong_t)ds->ds_prev_snap_obj);
	(void) printf("\t\tprev_snap_txg = %llu\n",
	    (u_longlong_t)ds->ds_prev_snap_txg);
	(void) printf("\t\tnext_snap_obj = %llu\n",
	    (u_longlong_t)ds->ds_next_snap_obj);
	(void) printf("\t\tsnapnames_zapobj = %llu\n",
	    (u_longlong_t)ds->ds_snapnames_zapobj);
	(void) printf("\t\tnum_children = %llu\n",
	    (u_longlong_t)ds->ds_num_children);
	(void) printf("\t\tuserrefs_obj = %llu\n",
	    (u_longlong_t)ds->ds_userrefs_obj);
	(void) printf("\t\tcreation_time = %s", ctime(&crtime));
	(void) printf("\t\tcreation_txg = %llu\n",
	    (u_longlong_t)ds->ds_creation_txg);
	(void) printf("\t\tdeadlist_obj = %llu\n",
	    (u_longlong_t)ds->ds_deadlist_obj);
	(void) printf("\t\tused_bytes = %s\n", used);
	(void) printf("\t\tcompressed_bytes = %s\n", compressed);
	(void) printf("\t\tuncompressed_bytes = %s\n", uncompressed);
	(void) printf("\t\tunique = %s\n", unique);
	(void) printf("\t\tfsid_guid = %llu\n",
	    (u_longlong_t)ds->ds_fsid_guid);
	(void) printf("\t\tguid = %llu\n",
	    (u_longlong_t)ds->ds_guid);
	(void) printf("\t\tflags = %llx\n",
	    (u_longlong_t)ds->ds_flags);
	(void) printf("\t\tnext_clones_obj = %llu\n",
	    (u_longlong_t)ds->ds_next_clones_obj);
	(void) printf("\t\tprops_obj = %llu\n",
	    (u_longlong_t)ds->ds_props_obj);
	(void) printf("\t\tbp = %s\n", blkbuf);
}

static int
dump_bptree_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
{
	(void) arg, (void) tx;
	char blkbuf[BP_SPRINTF_LEN];

	if (BP_GET_BIRTH(bp) != 0) {
		snprintf_blkptr(blkbuf, sizeof (blkbuf), bp);
		(void) printf("\t%s\n", blkbuf);
	}
	return (0);
}

static void
dump_bptree(objset_t *os, uint64_t obj, const char *name)
{
	char bytes[32];
	bptree_phys_t *bt;
	dmu_buf_t *db;

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (bytes) >= NN_NUMBUF_SZ, "bytes truncated");

	if (dump_opt['d'] < 3)
		return;

	VERIFY3U(0, ==, dmu_bonus_hold(os, obj, FTAG, &db));
	bt = db->db_data;
	zdb_nicenum(bt->bt_bytes, bytes, sizeof (bytes));
	(void) printf("\n    %s: %llu datasets, %s\n",
	    name, (unsigned long long)(bt->bt_end - bt->bt_begin), bytes);
	dmu_buf_rele(db, FTAG);

	if (dump_opt['d'] < 5)
		return;

	(void) printf("\n");

	(void) bptree_iterate(os, obj, B_FALSE, dump_bptree_cb, NULL, NULL);
}

static int
dump_bpobj_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed, dmu_tx_t *tx)
{
	(void) arg, (void) tx;
	char blkbuf[BP_SPRINTF_LEN];

	ASSERT(BP_GET_BIRTH(bp) != 0);
	snprintf_blkptr_compact(blkbuf, sizeof (blkbuf), bp, bp_freed);
	(void) printf("\t%s\n", blkbuf);
	return (0);
}

static void
dump_full_bpobj(bpobj_t *bpo, const char *name, int indent)
{
	char bytes[32];
	char comp[32];
	char uncomp[32];
	uint64_t i;

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (bytes) >= NN_NUMBUF_SZ, "bytes truncated");
	_Static_assert(sizeof (comp) >= NN_NUMBUF_SZ, "comp truncated");
	_Static_assert(sizeof (uncomp) >= NN_NUMBUF_SZ, "uncomp truncated");

	if (dump_opt['d'] < 3)
		return;

	zdb_nicenum(bpo->bpo_phys->bpo_bytes, bytes, sizeof (bytes));
	if (bpo->bpo_havesubobj && bpo->bpo_phys->bpo_subobjs != 0) {
		zdb_nicenum(bpo->bpo_phys->bpo_comp, comp, sizeof (comp));
		zdb_nicenum(bpo->bpo_phys->bpo_uncomp, uncomp, sizeof (uncomp));
		if (bpo->bpo_havefreed) {
			(void) printf("    %*s: object %llu, %llu local "
			    "blkptrs, %llu freed, %llu subobjs in object %llu, "
			    "%s (%s/%s comp)\n",
			    indent * 8, name,
			    (u_longlong_t)bpo->bpo_object,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_blkptrs,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_freed,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_subobjs,
			    (u_longlong_t)bpo->bpo_phys->bpo_subobjs,
			    bytes, comp, uncomp);
		} else {
			(void) printf("    %*s: object %llu, %llu local "
			    "blkptrs, %llu subobjs in object %llu, "
			    "%s (%s/%s comp)\n",
			    indent * 8, name,
			    (u_longlong_t)bpo->bpo_object,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_blkptrs,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_subobjs,
			    (u_longlong_t)bpo->bpo_phys->bpo_subobjs,
			    bytes, comp, uncomp);
		}

		for (i = 0; i < bpo->bpo_phys->bpo_num_subobjs; i++) {
			uint64_t subobj;
			bpobj_t subbpo;
			int error;
			VERIFY0(dmu_read(bpo->bpo_os,
			    bpo->bpo_phys->bpo_subobjs,
			    i * sizeof (subobj), sizeof (subobj), &subobj, 0));
			error = bpobj_open(&subbpo, bpo->bpo_os, subobj);
			if (error != 0) {
				(void) printf("ERROR %u while trying to open "
				    "subobj id %llu\n",
				    error, (u_longlong_t)subobj);
				corruption_found = B_TRUE;
				continue;
			}
			dump_full_bpobj(&subbpo, "subobj", indent + 1);
			bpobj_close(&subbpo);
		}
	} else {
		if (bpo->bpo_havefreed) {
			(void) printf("    %*s: object %llu, %llu blkptrs, "
			    "%llu freed, %s\n",
			    indent * 8, name,
			    (u_longlong_t)bpo->bpo_object,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_blkptrs,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_freed,
			    bytes);
		} else {
			(void) printf("    %*s: object %llu, %llu blkptrs, "
			    "%s\n",
			    indent * 8, name,
			    (u_longlong_t)bpo->bpo_object,
			    (u_longlong_t)bpo->bpo_phys->bpo_num_blkptrs,
			    bytes);
		}
	}

	if (dump_opt['d'] < 5)
		return;


	if (indent == 0) {
		(void) bpobj_iterate_nofree(bpo, dump_bpobj_cb, NULL, NULL);
		(void) printf("\n");
	}
}

static int
dump_bookmark(dsl_pool_t *dp, char *name, boolean_t print_redact,
    boolean_t print_list)
{
	int err = 0;
	zfs_bookmark_phys_t prop;
	objset_t *mos = dp->dp_spa->spa_meta_objset;
	err = dsl_bookmark_lookup(dp, name, NULL, &prop);

	if (err != 0) {
		return (err);
	}

	(void) printf("\t#%s: ", strchr(name, '#') + 1);
	(void) printf("{guid: %llx creation_txg: %llu creation_time: "
	    "%llu redaction_obj: %llu}\n", (u_longlong_t)prop.zbm_guid,
	    (u_longlong_t)prop.zbm_creation_txg,
	    (u_longlong_t)prop.zbm_creation_time,
	    (u_longlong_t)prop.zbm_redaction_obj);

	IMPLY(print_list, print_redact);
	if (!print_redact || prop.zbm_redaction_obj == 0)
		return (0);

	redaction_list_t *rl;
	VERIFY0(dsl_redaction_list_hold_obj(dp,
	    prop.zbm_redaction_obj, FTAG, &rl));

	redaction_list_phys_t *rlp = rl->rl_phys;
	(void) printf("\tRedacted:\n\t\tProgress: ");
	if (rlp->rlp_last_object != UINT64_MAX ||
	    rlp->rlp_last_blkid != UINT64_MAX) {
		(void) printf("%llu %llu (incomplete)\n",
		    (u_longlong_t)rlp->rlp_last_object,
		    (u_longlong_t)rlp->rlp_last_blkid);
	} else {
		(void) printf("complete\n");
	}
	(void) printf("\t\tSnapshots: [");
	for (unsigned int i = 0; i < rlp->rlp_num_snaps; i++) {
		if (i > 0)
			(void) printf(", ");
		(void) printf("%0llu",
		    (u_longlong_t)rlp->rlp_snaps[i]);
	}
	(void) printf("]\n\t\tLength: %llu\n",
	    (u_longlong_t)rlp->rlp_num_entries);

	if (!print_list) {
		dsl_redaction_list_rele(rl, FTAG);
		return (0);
	}

	if (rlp->rlp_num_entries == 0) {
		dsl_redaction_list_rele(rl, FTAG);
		(void) printf("\t\tRedaction List: []\n\n");
		return (0);
	}

	redact_block_phys_t *rbp_buf;
	uint64_t size;
	dmu_object_info_t doi;

	VERIFY0(dmu_object_info(mos, prop.zbm_redaction_obj, &doi));
	size = doi.doi_max_offset;
	rbp_buf = kmem_alloc(size, KM_SLEEP);

	err = dmu_read(mos, prop.zbm_redaction_obj, 0, size,
	    rbp_buf, 0);
	if (err != 0) {
		dsl_redaction_list_rele(rl, FTAG);
		kmem_free(rbp_buf, size);
		return (err);
	}

	(void) printf("\t\tRedaction List: [{object: %llx, offset: "
	    "%llx, blksz: %x, count: %llx}",
	    (u_longlong_t)rbp_buf[0].rbp_object,
	    (u_longlong_t)rbp_buf[0].rbp_blkid,
	    (uint_t)(redact_block_get_size(&rbp_buf[0])),
	    (u_longlong_t)redact_block_get_count(&rbp_buf[0]));

	for (size_t i = 1; i < rlp->rlp_num_entries; i++) {
		(void) printf(",\n\t\t{object: %llx, offset: %llx, "
		    "blksz: %x, count: %llx}",
		    (u_longlong_t)rbp_buf[i].rbp_object,
		    (u_longlong_t)rbp_buf[i].rbp_blkid,
		    (uint_t)(redact_block_get_size(&rbp_buf[i])),
		    (u_longlong_t)redact_block_get_count(&rbp_buf[i]));
	}
	dsl_redaction_list_rele(rl, FTAG);
	kmem_free(rbp_buf, size);
	(void) printf("]\n\n");
	return (0);
}

static void
dump_bookmarks(objset_t *os, int verbosity)
{
	zap_cursor_t zc;
	zap_attribute_t *attrp;
	dsl_dataset_t *ds = dmu_objset_ds(os);
	dsl_pool_t *dp = spa_get_dsl(os->os_spa);
	objset_t *mos = os->os_spa->spa_meta_objset;
	if (verbosity < 4)
		return;
	attrp = zap_attribute_alloc();
	dsl_pool_config_enter(dp, FTAG);

	for (zap_cursor_init(&zc, mos, ds->ds_bookmarks_obj);
	    zap_cursor_retrieve(&zc, attrp) == 0;
	    zap_cursor_advance(&zc)) {
		char osname[ZFS_MAX_DATASET_NAME_LEN];
		char buf[ZFS_MAX_DATASET_NAME_LEN];
		int len;
		dmu_objset_name(os, osname);
		len = snprintf(buf, sizeof (buf), "%s#%s", osname,
		    attrp->za_name);
		VERIFY3S(len, <, ZFS_MAX_DATASET_NAME_LEN);
		(void) dump_bookmark(dp, buf, verbosity >= 5, verbosity >= 6);
	}
	zap_cursor_fini(&zc);
	dsl_pool_config_exit(dp, FTAG);
	zap_attribute_free(attrp);
}

static void
bpobj_count_refd(bpobj_t *bpo)
{
	mos_obj_refd(bpo->bpo_object);

	if (bpo->bpo_havesubobj && bpo->bpo_phys->bpo_subobjs != 0) {
		mos_obj_refd(bpo->bpo_phys->bpo_subobjs);
		for (uint64_t i = 0; i < bpo->bpo_phys->bpo_num_subobjs; i++) {
			uint64_t subobj;
			bpobj_t subbpo;
			int error;
			VERIFY0(dmu_read(bpo->bpo_os,
			    bpo->bpo_phys->bpo_subobjs,
			    i * sizeof (subobj), sizeof (subobj), &subobj, 0));
			error = bpobj_open(&subbpo, bpo->bpo_os, subobj);
			if (error != 0) {
				(void) printf("ERROR %u while trying to open "
				    "subobj id %llu\n",
				    error, (u_longlong_t)subobj);
				corruption_found = B_TRUE;
				continue;
			}
			bpobj_count_refd(&subbpo);
			bpobj_close(&subbpo);
		}
	}
}

static int
dsl_deadlist_entry_count_refd(void *arg, dsl_deadlist_entry_t *dle)
{
	spa_t *spa = arg;
	uint64_t empty_bpobj = spa->spa_dsl_pool->dp_empty_bpobj;
	if (dle->dle_bpobj.bpo_object != empty_bpobj)
		bpobj_count_refd(&dle->dle_bpobj);
	return (0);
}

static int
dsl_deadlist_entry_dump(void *arg, dsl_deadlist_entry_t *dle)
{
	ASSERT0P(arg);
	if (dump_opt['d'] >= 5) {
		char buf[128];
		(void) snprintf(buf, sizeof (buf),
		    "mintxg %llu -> obj %llu",
		    (longlong_t)dle->dle_mintxg,
		    (longlong_t)dle->dle_bpobj.bpo_object);

		dump_full_bpobj(&dle->dle_bpobj, buf, 0);
	} else {
		(void) printf("mintxg %llu -> obj %llu\n",
		    (longlong_t)dle->dle_mintxg,
		    (longlong_t)dle->dle_bpobj.bpo_object);
	}
	return (0);
}

static void
dump_blkptr_list(dsl_deadlist_t *dl, const char *name)
{
	char bytes[32];
	char comp[32];
	char uncomp[32];
	char entries[32];
	spa_t *spa = dmu_objset_spa(dl->dl_os);
	uint64_t empty_bpobj = spa->spa_dsl_pool->dp_empty_bpobj;

	if (dl->dl_oldfmt) {
		if (dl->dl_bpobj.bpo_object != empty_bpobj)
			bpobj_count_refd(&dl->dl_bpobj);
	} else {
		mos_obj_refd(dl->dl_object);
		dsl_deadlist_iterate(dl, dsl_deadlist_entry_count_refd, spa);
	}

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (bytes) >= NN_NUMBUF_SZ, "bytes truncated");
	_Static_assert(sizeof (comp) >= NN_NUMBUF_SZ, "comp truncated");
	_Static_assert(sizeof (uncomp) >= NN_NUMBUF_SZ, "uncomp truncated");
	_Static_assert(sizeof (entries) >= NN_NUMBUF_SZ, "entries truncated");

	if (dump_opt['d'] < 3)
		return;

	if (dl->dl_oldfmt) {
		dump_full_bpobj(&dl->dl_bpobj, "old-format deadlist", 0);
		return;
	}

	zdb_nicenum(dl->dl_phys->dl_used, bytes, sizeof (bytes));
	zdb_nicenum(dl->dl_phys->dl_comp, comp, sizeof (comp));
	zdb_nicenum(dl->dl_phys->dl_uncomp, uncomp, sizeof (uncomp));
	zdb_nicenum(avl_numnodes(&dl->dl_tree), entries, sizeof (entries));
	(void) printf("\n    %s: %s (%s/%s comp), %s entries\n",
	    name, bytes, comp, uncomp, entries);

	if (dump_opt['d'] < 4)
		return;

	(void) putchar('\n');

	dsl_deadlist_iterate(dl, dsl_deadlist_entry_dump, NULL);
}

static int
verify_dd_livelist(objset_t *os)
{
	uint64_t ll_used, used, ll_comp, comp, ll_uncomp, uncomp;
	dsl_pool_t *dp = spa_get_dsl(os->os_spa);
	dsl_dir_t  *dd = os->os_dsl_dataset->ds_dir;

	ASSERT(!dmu_objset_is_snapshot(os));
	if (!dsl_deadlist_is_open(&dd->dd_livelist))
		return (0);

	/* Iterate through the livelist to check for duplicates */
	dsl_deadlist_iterate(&dd->dd_livelist, sublivelist_verify_lightweight,
	    NULL);

	dsl_pool_config_enter(dp, FTAG);
	dsl_deadlist_space(&dd->dd_livelist, &ll_used,
	    &ll_comp, &ll_uncomp);

	dsl_dataset_t *origin_ds;
	ASSERT(dsl_pool_config_held(dp));
	VERIFY0(dsl_dataset_hold_obj(dp,
	    dsl_dir_phys(dd)->dd_origin_obj, FTAG, &origin_ds));
	VERIFY0(dsl_dataset_space_written(origin_ds, os->os_dsl_dataset,
	    &used, &comp, &uncomp));
	dsl_dataset_rele(origin_ds, FTAG);
	dsl_pool_config_exit(dp, FTAG);
	/*
	 *  It's possible that the dataset's uncomp space is larger than the
	 *  livelist's because livelists do not track embedded block pointers
	 */
	if (used != ll_used || comp != ll_comp || uncomp < ll_uncomp) {
		char nice_used[32], nice_comp[32], nice_uncomp[32];
		(void) printf("Discrepancy in space accounting:\n");
		zdb_nicenum(used, nice_used, sizeof (nice_used));
		zdb_nicenum(comp, nice_comp, sizeof (nice_comp));
		zdb_nicenum(uncomp, nice_uncomp, sizeof (nice_uncomp));
		(void) printf("dir: used %s, comp %s, uncomp %s\n",
		    nice_used, nice_comp, nice_uncomp);
		zdb_nicenum(ll_used, nice_used, sizeof (nice_used));
		zdb_nicenum(ll_comp, nice_comp, sizeof (nice_comp));
		zdb_nicenum(ll_uncomp, nice_uncomp, sizeof (nice_uncomp));
		(void) printf("livelist: used %s, comp %s, uncomp %s\n",
		    nice_used, nice_comp, nice_uncomp);
		return (1);
	}
	return (0);
}

static char *key_material = NULL;

static boolean_t
zdb_derive_key(dsl_dir_t *dd, uint8_t *key_out)
{
	uint64_t keyformat, salt, iters;
	int i;
	unsigned char c;

	VERIFY0(zap_lookup(dd->dd_pool->dp_meta_objset, dd->dd_crypto_obj,
	    zfs_prop_to_name(ZFS_PROP_KEYFORMAT), sizeof (uint64_t),
	    1, &keyformat));

	switch (keyformat) {
	case ZFS_KEYFORMAT_HEX:
		for (i = 0; i < WRAPPING_KEY_LEN * 2; i += 2) {
			if (!isxdigit(key_material[i]) ||
			    !isxdigit(key_material[i+1]))
				return (B_FALSE);
			if (sscanf(&key_material[i], "%02hhx", &c) != 1)
				return (B_FALSE);
			key_out[i / 2] = c;
		}
		break;

	case ZFS_KEYFORMAT_PASSPHRASE:
		VERIFY0(zap_lookup(dd->dd_pool->dp_meta_objset,
		    dd->dd_crypto_obj, zfs_prop_to_name(ZFS_PROP_PBKDF2_SALT),
		    sizeof (uint64_t), 1, &salt));
		VERIFY0(zap_lookup(dd->dd_pool->dp_meta_objset,
		    dd->dd_crypto_obj, zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS),
		    sizeof (uint64_t), 1, &iters));

		if (PKCS5_PBKDF2_HMAC_SHA1(key_material, strlen(key_material),
		    ((uint8_t *)&salt), sizeof (uint64_t), iters,
		    WRAPPING_KEY_LEN, key_out) != 1)
			return (B_FALSE);

		break;

	default:
		fatal("no support for key format %u\n",
		    (unsigned int) keyformat);
	}

	return (B_TRUE);
}

static char encroot[ZFS_MAX_DATASET_NAME_LEN];
static boolean_t key_loaded = B_FALSE;

static void
zdb_load_key(objset_t *os)
{
	dsl_pool_t *dp;
	dsl_dir_t *dd, *rdd;
	uint8_t key[WRAPPING_KEY_LEN];
	uint64_t rddobj;
	int err;

	dp = spa_get_dsl(os->os_spa);
	dd = os->os_dsl_dataset->ds_dir;

	dsl_pool_config_enter(dp, FTAG);
	VERIFY0(zap_lookup(dd->dd_pool->dp_meta_objset, dd->dd_crypto_obj,
	    DSL_CRYPTO_KEY_ROOT_DDOBJ, sizeof (uint64_t), 1, &rddobj));
	VERIFY0(dsl_dir_hold_obj(dd->dd_pool, rddobj, NULL, FTAG, &rdd));
	dsl_dir_name(rdd, encroot);
	dsl_dir_rele(rdd, FTAG);

	if (!zdb_derive_key(dd, key))
		fatal("couldn't derive encryption key");

	dsl_pool_config_exit(dp, FTAG);

	ASSERT3U(dsl_dataset_get_keystatus(dd), ==, ZFS_KEYSTATUS_UNAVAILABLE);

	dsl_crypto_params_t *dcp;
	nvlist_t *crypto_args;

	crypto_args = fnvlist_alloc();
	fnvlist_add_uint8_array(crypto_args, "wkeydata",
	    (uint8_t *)key, WRAPPING_KEY_LEN);
	VERIFY0(dsl_crypto_params_create_nvlist(DCP_CMD_NONE,
	    NULL, crypto_args, &dcp));
	err = spa_keystore_load_wkey(encroot, dcp, B_FALSE);

	dsl_crypto_params_free(dcp, (err != 0));
	fnvlist_free(crypto_args);

	if (err != 0)
		fatal(
		    "couldn't load encryption key for %s: %s",
		    encroot, err == ZFS_ERR_CRYPTO_NOTSUP ?
		    "crypto params not supported" : strerror(err));

	ASSERT3U(dsl_dataset_get_keystatus(dd), ==, ZFS_KEYSTATUS_AVAILABLE);

	printf("Unlocked encryption root: %s\n", encroot);
	key_loaded = B_TRUE;
}

static void
zdb_unload_key(void)
{
	if (!key_loaded)
		return;

	VERIFY0(spa_keystore_unload_wkey(encroot));
	key_loaded = B_FALSE;
}

static avl_tree_t idx_tree;
static avl_tree_t domain_tree;
static boolean_t fuid_table_loaded;
static objset_t *sa_os = NULL;
static sa_attr_type_t *sa_attr_table = NULL;

static int
open_objset(const char *path, const void *tag, objset_t **osp)
{
	int err;
	uint64_t sa_attrs = 0;
	uint64_t version = 0;

	VERIFY0P(sa_os);

	/*
	 * We can't own an objset if it's redacted.  Therefore, we do this
	 * dance: hold the objset, then acquire a long hold on its dataset, then
	 * release the pool (which is held as part of holding the objset).
	 */

	if (dump_opt['K']) {
		/* decryption requested, try to load keys */
		err = dmu_objset_hold(path, tag, osp);
		if (err != 0) {
			(void) fprintf(stderr, "failed to hold dataset "
			    "'%s': %s\n",
			    path, strerror(err));
			return (err);
		}
		dsl_dataset_long_hold(dmu_objset_ds(*osp), tag);
		dsl_pool_rele(dmu_objset_pool(*osp), tag);

		/* succeeds or dies */
		zdb_load_key(*osp);

		/* release it all */
		dsl_dataset_long_rele(dmu_objset_ds(*osp), tag);
		dsl_dataset_rele(dmu_objset_ds(*osp), tag);
	}

	int ds_hold_flags = key_loaded ? DS_HOLD_FLAG_DECRYPT : 0;

	err = dmu_objset_hold_flags(path, ds_hold_flags, tag, osp);
	if (err != 0) {
		(void) fprintf(stderr, "failed to hold dataset '%s': %s\n",
		    path, strerror(err));
		return (err);
	}
	dsl_dataset_long_hold(dmu_objset_ds(*osp), tag);
	dsl_pool_rele(dmu_objset_pool(*osp), tag);

	if (dmu_objset_type(*osp) == DMU_OST_ZFS &&
	    (key_loaded || !(*osp)->os_encrypted)) {
		(void) zap_lookup(*osp, MASTER_NODE_OBJ, ZPL_VERSION_STR,
		    8, 1, &version);
		if (version >= ZPL_VERSION_SA) {
			(void) zap_lookup(*osp, MASTER_NODE_OBJ, ZFS_SA_ATTRS,
			    8, 1, &sa_attrs);
		}
		err = sa_setup(*osp, sa_attrs, zfs_attr_table, ZPL_END,
		    &sa_attr_table);
		if (err != 0) {
			(void) fprintf(stderr, "sa_setup failed: %s\n",
			    strerror(err));
			dsl_dataset_long_rele(dmu_objset_ds(*osp), tag);
			dsl_dataset_rele_flags(dmu_objset_ds(*osp),
			    ds_hold_flags, tag);
			*osp = NULL;
		}
	}
	sa_os = *osp;

	return (err);
}

static void
close_objset(objset_t *os, const void *tag)
{
	VERIFY3P(os, ==, sa_os);
	if (os->os_sa != NULL)
		sa_tear_down(os);
	dsl_dataset_long_rele(dmu_objset_ds(os), tag);
	dsl_dataset_rele_flags(dmu_objset_ds(os),
	    key_loaded ? DS_HOLD_FLAG_DECRYPT : 0, tag);
	sa_attr_table = NULL;
	sa_os = NULL;

	zdb_unload_key();
}

static void
fuid_table_destroy(void)
{
	if (fuid_table_loaded) {
		zfs_fuid_table_destroy(&idx_tree, &domain_tree);
		fuid_table_loaded = B_FALSE;
	}
}

/*
 * Clean up DDT internal state. ddt_lookup() adds entries to ddt_tree, which on
 * a live pool are normally cleaned up during ddt_sync(). We can't do that (and
 * wouldn't want to anyway), but if we don't clean up the presence of stuff on
 * ddt_tree will trip asserts in ddt_table_free(). So, we clean up ourselves.
 *
 * Note that this is not a particularly efficient way to do this, but
 * ddt_remove() is the only public method that can do the work we need, and it
 * requires the right locks and etc to do the job. This is only ever called
 * during zdb shutdown so efficiency is not especially important.
 */
static void
zdb_ddt_cleanup(spa_t *spa)
{
	for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
		ddt_t *ddt = spa->spa_ddt[c];
		if (!ddt)
			continue;

		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
		ddt_enter(ddt);
		ddt_entry_t *dde = avl_first(&ddt->ddt_tree), *next;
		while (dde) {
			next = AVL_NEXT(&ddt->ddt_tree, dde);
			dde->dde_io = NULL;
			ddt_remove(ddt, dde);
			dde = next;
		}
		ddt_exit(ddt);
		spa_config_exit(spa, SCL_CONFIG, FTAG);
	}
}

static void
zdb_exit(int reason)
{
	if (spa != NULL)
		zdb_ddt_cleanup(spa);

	if (os != NULL) {
		close_objset(os, FTAG);
	} else if (spa != NULL) {
		spa_close(spa, FTAG);
	}

	fuid_table_destroy();

	if (kernel_init_done)
		kernel_fini();

	exit(reason);
}

/*
 * print uid or gid information.
 * For normal POSIX id just the id is printed in decimal format.
 * For CIFS files with FUID the fuid is printed in hex followed by
 * the domain-rid string.
 */
static void
print_idstr(uint64_t id, const char *id_type)
{
	if (FUID_INDEX(id)) {
		const char *domain =
		    zfs_fuid_idx_domain(&idx_tree, FUID_INDEX(id));
		(void) printf("\t%s     %llx [%s-%d]\n", id_type,
		    (u_longlong_t)id, domain, (int)FUID_RID(id));
	} else {
		(void) printf("\t%s     %llu\n", id_type, (u_longlong_t)id);
	}

}

static void
dump_uidgid(objset_t *os, uint64_t uid, uint64_t gid)
{
	uint32_t uid_idx, gid_idx;

	uid_idx = FUID_INDEX(uid);
	gid_idx = FUID_INDEX(gid);

	/* Load domain table, if not already loaded */
	if (!fuid_table_loaded && (uid_idx || gid_idx)) {
		uint64_t fuid_obj;

		/* first find the fuid object.  It lives in the master node */
		VERIFY0(zap_lookup(os, MASTER_NODE_OBJ, ZFS_FUID_TABLES,
		    8, 1, &fuid_obj));
		zfs_fuid_avl_tree_create(&idx_tree, &domain_tree);
		(void) zfs_fuid_table_load(os, fuid_obj,
		    &idx_tree, &domain_tree);
		fuid_table_loaded = B_TRUE;
	}

	print_idstr(uid, "uid");
	print_idstr(gid, "gid");
}

static void
dump_znode_sa_xattr(sa_handle_t *hdl)
{
	nvlist_t *sa_xattr;
	nvpair_t *elem = NULL;
	int sa_xattr_size = 0;
	int sa_xattr_entries = 0;
	int error;
	char *sa_xattr_packed;

	error = sa_size(hdl, sa_attr_table[ZPL_DXATTR], &sa_xattr_size);
	if (error || sa_xattr_size == 0)
		return;

	sa_xattr_packed = malloc(sa_xattr_size);
	if (sa_xattr_packed == NULL)
		return;

	error = sa_lookup(hdl, sa_attr_table[ZPL_DXATTR],
	    sa_xattr_packed, sa_xattr_size);
	if (error) {
		free(sa_xattr_packed);
		return;
	}

	error = nvlist_unpack(sa_xattr_packed, sa_xattr_size, &sa_xattr, 0);
	if (error) {
		free(sa_xattr_packed);
		return;
	}

	while ((elem = nvlist_next_nvpair(sa_xattr, elem)) != NULL)
		sa_xattr_entries++;

	(void) printf("\tSA xattrs: %d bytes, %d entries\n\n",
	    sa_xattr_size, sa_xattr_entries);
	while ((elem = nvlist_next_nvpair(sa_xattr, elem)) != NULL) {
		boolean_t can_print = !dump_opt['P'];
		uchar_t *value;
		uint_t cnt, idx;

		(void) printf("\t\t%s = ", nvpair_name(elem));
		nvpair_value_byte_array(elem, &value, &cnt);

		for (idx = 0; idx < cnt; ++idx) {
			if (!isprint(value[idx])) {
				can_print = B_FALSE;
				break;
			}
		}

		for (idx = 0; idx < cnt; ++idx) {
			if (can_print)
				(void) putchar(value[idx]);
			else
				(void) printf("\\%3.3o", value[idx]);
		}
		(void) putchar('\n');
	}

	nvlist_free(sa_xattr);
	free(sa_xattr_packed);
}

static void
dump_znode_symlink(sa_handle_t *hdl)
{
	int sa_symlink_size = 0;
	char linktarget[MAXPATHLEN];
	int error;

	error = sa_size(hdl, sa_attr_table[ZPL_SYMLINK], &sa_symlink_size);
	if (error || sa_symlink_size == 0) {
		return;
	}
	if (sa_symlink_size >= sizeof (linktarget)) {
		(void) printf("symlink size %d is too large\n",
		    sa_symlink_size);
		return;
	}
	linktarget[sa_symlink_size] = '\0';
	if (sa_lookup(hdl, sa_attr_table[ZPL_SYMLINK],
	    &linktarget, sa_symlink_size) == 0)
		(void) printf("\ttarget	%s\n", linktarget);
}

static void
dump_znode(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) data, (void) size;
	char path[MAXPATHLEN * 2];	/* allow for xattr and failure prefix */
	sa_handle_t *hdl;
	uint64_t xattr, rdev, gen;
	uint64_t uid, gid, mode, fsize, parent, links;
	uint64_t pflags;
	uint64_t acctm[2], modtm[2], chgtm[2], crtm[2];
	time_t z_crtime, z_atime, z_mtime, z_ctime;
	sa_bulk_attr_t bulk[12];
	int idx = 0;
	int error;

	VERIFY3P(os, ==, sa_os);
	if (sa_handle_get(os, object, NULL, SA_HDL_PRIVATE, &hdl)) {
		(void) printf("Failed to get handle for SA znode\n");
		return;
	}

	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_UID], NULL, &uid, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_GID], NULL, &gid, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_LINKS], NULL,
	    &links, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_GEN], NULL, &gen, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_MODE], NULL,
	    &mode, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_PARENT],
	    NULL, &parent, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_SIZE], NULL,
	    &fsize, 8);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_ATIME], NULL,
	    acctm, 16);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_MTIME], NULL,
	    modtm, 16);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_CRTIME], NULL,
	    crtm, 16);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_CTIME], NULL,
	    chgtm, 16);
	SA_ADD_BULK_ATTR(bulk, idx, sa_attr_table[ZPL_FLAGS], NULL,
	    &pflags, 8);

	if (sa_bulk_lookup(hdl, bulk, idx)) {
		(void) sa_handle_destroy(hdl);
		return;
	}

	z_crtime = (time_t)crtm[0];
	z_atime = (time_t)acctm[0];
	z_mtime = (time_t)modtm[0];
	z_ctime = (time_t)chgtm[0];

	if (dump_opt['d'] > 4) {
		error = zfs_obj_to_path(os, object, path, sizeof (path));
		if (error == ESTALE) {
			(void) snprintf(path, sizeof (path), "on delete queue");
		} else if (error != 0) {
			leaked_objects++;
			(void) snprintf(path, sizeof (path),
			    "path not found, possibly leaked");
		}
		(void) printf("\tpath	%s\n", path);
	}

	if (S_ISLNK(mode))
		dump_znode_symlink(hdl);
	dump_uidgid(os, uid, gid);
	(void) printf("\tatime	%s", ctime(&z_atime));
	(void) printf("\tmtime	%s", ctime(&z_mtime));
	(void) printf("\tctime	%s", ctime(&z_ctime));
	(void) printf("\tcrtime	%s", ctime(&z_crtime));
	(void) printf("\tgen	%llu\n", (u_longlong_t)gen);
	(void) printf("\tmode	%llo\n", (u_longlong_t)mode);
	(void) printf("\tsize	%llu\n", (u_longlong_t)fsize);
	(void) printf("\tparent	%llu\n", (u_longlong_t)parent);
	(void) printf("\tlinks	%llu\n", (u_longlong_t)links);
	(void) printf("\tpflags	%llx\n", (u_longlong_t)pflags);
	if (dmu_objset_projectquota_enabled(os) && (pflags & ZFS_PROJID)) {
		uint64_t projid;

		if (sa_lookup(hdl, sa_attr_table[ZPL_PROJID], &projid,
		    sizeof (uint64_t)) == 0)
			(void) printf("\tprojid	%llu\n", (u_longlong_t)projid);
	}
	if (sa_lookup(hdl, sa_attr_table[ZPL_XATTR], &xattr,
	    sizeof (uint64_t)) == 0)
		(void) printf("\txattr	%llu\n", (u_longlong_t)xattr);
	if (sa_lookup(hdl, sa_attr_table[ZPL_RDEV], &rdev,
	    sizeof (uint64_t)) == 0)
		(void) printf("\trdev	0x%016llx\n", (u_longlong_t)rdev);
	dump_znode_sa_xattr(hdl);
	sa_handle_destroy(hdl);
}

static void
dump_acl(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) data, (void) size;
}

static void
dump_dmu_objset(objset_t *os, uint64_t object, void *data, size_t size)
{
	(void) os, (void) object, (void) data, (void) size;
}

static object_viewer_t *object_viewer[DMU_OT_NUMTYPES + 1] = {
	dump_none,		/* unallocated			*/
	dump_zap,		/* object directory		*/
	dump_uint64,		/* object array			*/
	dump_none,		/* packed nvlist		*/
	dump_packed_nvlist,	/* packed nvlist size		*/
	dump_none,		/* bpobj			*/
	dump_bpobj,		/* bpobj header			*/
	dump_none,		/* SPA space map header		*/
	dump_none,		/* SPA space map		*/
	dump_none,		/* ZIL intent log		*/
	dump_dnode,		/* DMU dnode			*/
	dump_dmu_objset,	/* DMU objset			*/
	dump_dsl_dir,		/* DSL directory		*/
	dump_zap,		/* DSL directory child map	*/
	dump_zap,		/* DSL dataset snap map		*/
	dump_zap,		/* DSL props			*/
	dump_dsl_dataset,	/* DSL dataset			*/
	dump_znode,		/* ZFS znode			*/
	dump_acl,		/* ZFS V0 ACL			*/
	dump_uint8,		/* ZFS plain file		*/
	dump_zpldir,		/* ZFS directory		*/
	dump_zap,		/* ZFS master node		*/
	dump_zap,		/* ZFS delete queue		*/
	dump_uint8,		/* zvol object			*/
	dump_zap,		/* zvol prop			*/
	dump_uint8,		/* other uint8[]		*/
	dump_uint64,		/* other uint64[]		*/
	dump_zap,		/* other ZAP			*/
	dump_zap,		/* persistent error log		*/
	dump_uint8,		/* SPA history			*/
	dump_history_offsets,	/* SPA history offsets		*/
	dump_zap,		/* Pool properties		*/
	dump_zap,		/* DSL permissions		*/
	dump_acl,		/* ZFS ACL			*/
	dump_uint8,		/* ZFS SYSACL			*/
	dump_none,		/* FUID nvlist			*/
	dump_packed_nvlist,	/* FUID nvlist size		*/
	dump_zap,		/* DSL dataset next clones	*/
	dump_zap,		/* DSL scrub queue		*/
	dump_zap,		/* ZFS user/group/project used	*/
	dump_zap,		/* ZFS user/group/project quota	*/
	dump_zap,		/* snapshot refcount tags	*/
	dump_ddt_zap,		/* DDT ZAP object		*/
	dump_zap,		/* DDT statistics		*/
	dump_znode,		/* SA object			*/
	dump_zap,		/* SA Master Node		*/
	dump_sa_attrs,		/* SA attribute registration	*/
	dump_sa_layouts,	/* SA attribute layouts		*/
	dump_zap,		/* DSL scrub translations	*/
	dump_none,		/* fake dedup BP		*/
	dump_zap,		/* deadlist			*/
	dump_none,		/* deadlist hdr			*/
	dump_zap,		/* dsl clones			*/
	dump_bpobj_subobjs,	/* bpobj subobjs		*/
	dump_unknown,		/* Unknown type, must be last	*/
};

static boolean_t
match_object_type(dmu_object_type_t obj_type, uint64_t flags)
{
	boolean_t match = B_TRUE;

	switch (obj_type) {
	case DMU_OT_DIRECTORY_CONTENTS:
		if (!(flags & ZOR_FLAG_DIRECTORY))
			match = B_FALSE;
		break;
	case DMU_OT_PLAIN_FILE_CONTENTS:
		if (!(flags & ZOR_FLAG_PLAIN_FILE))
			match = B_FALSE;
		break;
	case DMU_OT_SPACE_MAP:
		if (!(flags & ZOR_FLAG_SPACE_MAP))
			match = B_FALSE;
		break;
	default:
		if (strcmp(zdb_ot_name(obj_type), "zap") == 0) {
			if (!(flags & ZOR_FLAG_ZAP))
				match = B_FALSE;
			break;
		}

		/*
		 * If all bits except some of the supported flags are
		 * set, the user combined the all-types flag (A) with
		 * a negated flag to exclude some types (e.g. A-f to
		 * show all object types except plain files).
		 */
		if ((flags | ZOR_SUPPORTED_FLAGS) != ZOR_FLAG_ALL_TYPES)
			match = B_FALSE;

		break;
	}

	return (match);
}

static void
dump_object(objset_t *os, uint64_t object, int verbosity,
    boolean_t *print_header, uint64_t *dnode_slots_used, uint64_t flags)
{
	dmu_buf_t *db = NULL;
	dmu_object_info_t doi;
	dnode_t *dn;
	boolean_t dnode_held = B_FALSE;
	void *bonus = NULL;
	size_t bsize = 0;
	char iblk[32], dblk[32], lsize[32], asize[32], fill[32], dnsize[32];
	char bonus_size[32];
	char aux[50];
	int error;

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (iblk) >= NN_NUMBUF_SZ, "iblk truncated");
	_Static_assert(sizeof (dblk) >= NN_NUMBUF_SZ, "dblk truncated");
	_Static_assert(sizeof (lsize) >= NN_NUMBUF_SZ, "lsize truncated");
	_Static_assert(sizeof (asize) >= NN_NUMBUF_SZ, "asize truncated");
	_Static_assert(sizeof (bonus_size) >= NN_NUMBUF_SZ,
	    "bonus_size truncated");

	if (*print_header) {
		(void) printf("\n%10s  %3s  %5s  %5s  %5s  %6s  %5s  %6s  %s\n",
		    "Object", "lvl", "iblk", "dblk", "dsize", "dnsize",
		    "lsize", "%full", "type");
		*print_header = 0;
	}

	if (object == 0) {
		dn = DMU_META_DNODE(os);
		dmu_object_info_from_dnode(dn, &doi);
	} else {
		/*
		 * Encrypted datasets will have sensitive bonus buffers
		 * encrypted. Therefore we cannot hold the bonus buffer and
		 * must hold the dnode itself instead.
		 */
		error = dmu_object_info(os, object, &doi);
		if (error)
			fatal("dmu_object_info() failed, errno %u", error);

		if (!key_loaded && os->os_encrypted &&
		    DMU_OT_IS_ENCRYPTED(doi.doi_bonus_type)) {
			error = dnode_hold(os, object, FTAG, &dn);
			if (error)
				fatal("dnode_hold() failed, errno %u", error);
			dnode_held = B_TRUE;
		} else {
			error = dmu_bonus_hold(os, object, FTAG, &db);
			if (error)
				fatal("dmu_bonus_hold(%llu) failed, errno %u",
				    object, error);
			bonus = db->db_data;
			bsize = db->db_size;
			dn = DB_DNODE((dmu_buf_impl_t *)db);
		}
	}

	/*
	 * Default to showing all object types if no flags were specified.
	 */
	if (flags != 0 && flags != ZOR_FLAG_ALL_TYPES &&
	    !match_object_type(doi.doi_type, flags))
		goto out;

	if (dnode_slots_used)
		*dnode_slots_used = doi.doi_dnodesize / DNODE_MIN_SIZE;

	zdb_nicenum(doi.doi_metadata_block_size, iblk, sizeof (iblk));
	zdb_nicenum(doi.doi_data_block_size, dblk, sizeof (dblk));
	zdb_nicenum(doi.doi_max_offset, lsize, sizeof (lsize));
	zdb_nicenum(doi.doi_physical_blocks_512 << 9, asize, sizeof (asize));
	zdb_nicenum(doi.doi_bonus_size, bonus_size, sizeof (bonus_size));
	zdb_nicenum(doi.doi_dnodesize, dnsize, sizeof (dnsize));
	(void) snprintf(fill, sizeof (fill), "%6.2f", 100.0 *
	    doi.doi_fill_count * doi.doi_data_block_size / (object == 0 ?
	    DNODES_PER_BLOCK : 1) / doi.doi_max_offset);

	aux[0] = '\0';

	if (doi.doi_checksum != ZIO_CHECKSUM_INHERIT || verbosity >= 6) {
		(void) snprintf(aux + strlen(aux), sizeof (aux) - strlen(aux),
		    " (K=%s)", ZDB_CHECKSUM_NAME(doi.doi_checksum));
	}

	if (doi.doi_compress == ZIO_COMPRESS_INHERIT &&
	    ZIO_COMPRESS_HASLEVEL(os->os_compress) && verbosity >= 6) {
		const char *compname = NULL;
		if (zfs_prop_index_to_string(ZFS_PROP_COMPRESSION,
		    ZIO_COMPRESS_RAW(os->os_compress, os->os_complevel),
		    &compname) == 0) {
			(void) snprintf(aux + strlen(aux),
			    sizeof (aux) - strlen(aux), " (Z=inherit=%s)",
			    compname);
		} else {
			(void) snprintf(aux + strlen(aux),
			    sizeof (aux) - strlen(aux),
			    " (Z=inherit=%s-unknown)",
			    ZDB_COMPRESS_NAME(os->os_compress));
		}
	} else if (doi.doi_compress == ZIO_COMPRESS_INHERIT && verbosity >= 6) {
		(void) snprintf(aux + strlen(aux), sizeof (aux) - strlen(aux),
		    " (Z=inherit=%s)", ZDB_COMPRESS_NAME(os->os_compress));
	} else if (doi.doi_compress != ZIO_COMPRESS_INHERIT || verbosity >= 6) {
		(void) snprintf(aux + strlen(aux), sizeof (aux) - strlen(aux),
		    " (Z=%s)", ZDB_COMPRESS_NAME(doi.doi_compress));
	}

	(void) printf("%10lld  %3u  %5s  %5s  %5s  %6s  %5s  %6s  %s%s\n",
	    (u_longlong_t)object, doi.doi_indirection, iblk, dblk,
	    asize, dnsize, lsize, fill, zdb_ot_name(doi.doi_type), aux);

	if (doi.doi_bonus_type != DMU_OT_NONE && verbosity > 3) {
		(void) printf("%10s  %3s  %5s  %5s  %5s  %5s  %5s  %6s  %s\n",
		    "", "", "", "", "", "", bonus_size, "bonus",
		    zdb_ot_name(doi.doi_bonus_type));
	}

	if (verbosity >= 4) {
		(void) printf("\tdnode flags: %s%s%s%s\n",
		    (dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) ?
		    "USED_BYTES " : "",
		    (dn->dn_phys->dn_flags & DNODE_FLAG_USERUSED_ACCOUNTED) ?
		    "USERUSED_ACCOUNTED " : "",
		    (dn->dn_phys->dn_flags & DNODE_FLAG_USEROBJUSED_ACCOUNTED) ?
		    "USEROBJUSED_ACCOUNTED " : "",
		    (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) ?
		    "SPILL_BLKPTR" : "");
		(void) printf("\tdnode maxblkid: %llu\n",
		    (longlong_t)dn->dn_phys->dn_maxblkid);

		if (!dnode_held) {
			object_viewer[ZDB_OT_TYPE(doi.doi_bonus_type)](os,
			    object, bonus, bsize);
		} else {
			(void) printf("\t\t(bonus encrypted)\n");
		}

		if (key_loaded ||
		    (!os->os_encrypted || !DMU_OT_IS_ENCRYPTED(doi.doi_type))) {
			object_viewer[ZDB_OT_TYPE(doi.doi_type)](os, object,
			    NULL, 0);
		} else {
			(void) printf("\t\t(object encrypted)\n");
		}

		*print_header = B_TRUE;
	}

	if (verbosity >= 5) {
		if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
			char blkbuf[BP_SPRINTF_LEN];
			snprintf_blkptr_compact(blkbuf, sizeof (blkbuf),
			    DN_SPILL_BLKPTR(dn->dn_phys), B_FALSE);
			(void) printf("\nSpill block: %s\n", blkbuf);
		}
		dump_indirect(dn);
	}

	if (verbosity >= 5) {
		/*
		 * Report the list of segments that comprise the object.
		 */
		uint64_t start = 0;
		uint64_t end;
		uint64_t blkfill = 1;
		int minlvl = 1;

		if (dn->dn_type == DMU_OT_DNODE) {
			minlvl = 0;
			blkfill = DNODES_PER_BLOCK;
		}

		for (;;) {
			char segsize[32];
			/* make sure nicenum has enough space */
			_Static_assert(sizeof (segsize) >= NN_NUMBUF_SZ,
			    "segsize truncated");
			error = dnode_next_offset(dn,
			    0, &start, minlvl, blkfill, 0);
			if (error)
				break;
			end = start;
			error = dnode_next_offset(dn,
			    DNODE_FIND_HOLE, &end, minlvl, blkfill, 0);
			zdb_nicenum(end - start, segsize, sizeof (segsize));
			(void) printf("\t\tsegment [%016llx, %016llx)"
			    " size %5s\n", (u_longlong_t)start,
			    (u_longlong_t)end, segsize);
			if (error)
				break;
			start = end;
		}
	}

out:
	if (db != NULL)
		dmu_buf_rele(db, FTAG);
	if (dnode_held)
		dnode_rele(dn, FTAG);
}

static void
count_dir_mos_objects(dsl_dir_t *dd)
{
	mos_obj_refd(dd->dd_object);
	mos_obj_refd(dsl_dir_phys(dd)->dd_child_dir_zapobj);
	mos_obj_refd(dsl_dir_phys(dd)->dd_deleg_zapobj);
	mos_obj_refd(dsl_dir_phys(dd)->dd_props_zapobj);
	mos_obj_refd(dsl_dir_phys(dd)->dd_clones);

	/*
	 * The dd_crypto_obj can be referenced by multiple dsl_dir's.
	 * Ignore the references after the first one.
	 */
	mos_obj_refd_multiple(dd->dd_crypto_obj);
}

static void
count_ds_mos_objects(dsl_dataset_t *ds)
{
	mos_obj_refd(ds->ds_object);
	mos_obj_refd(dsl_dataset_phys(ds)->ds_next_clones_obj);
	mos_obj_refd(dsl_dataset_phys(ds)->ds_props_obj);
	mos_obj_refd(dsl_dataset_phys(ds)->ds_userrefs_obj);
	mos_obj_refd(dsl_dataset_phys(ds)->ds_snapnames_zapobj);
	mos_obj_refd(ds->ds_bookmarks_obj);

	if (!dsl_dataset_is_snapshot(ds)) {
		count_dir_mos_objects(ds->ds_dir);
	}
}

static const char *const objset_types[DMU_OST_NUMTYPES] = {
	"NONE", "META", "ZPL", "ZVOL", "OTHER", "ANY" };

/*
 * Parse a string denoting a range of object IDs of the form
 * <start>[:<end>[:flags]], and store the results in zor.
 * Return 0 on success. On error, return 1 and update the msg
 * pointer to point to a descriptive error message.
 */
static int
parse_object_range(char *range, zopt_object_range_t *zor, const char **msg)
{
	uint64_t flags = 0;
	char *p, *s, *dup, *flagstr, *tmp = NULL;
	size_t len;
	int i;
	int rc = 0;

	if (strchr(range, ':') == NULL) {
		zor->zor_obj_start = strtoull(range, &p, 0);
		if (*p != '\0') {
			*msg = "Invalid characters in object ID";
			rc = 1;
		}
		zor->zor_obj_start = ZDB_MAP_OBJECT_ID(zor->zor_obj_start);
		zor->zor_obj_end = zor->zor_obj_start;
		return (rc);
	}

	if (strchr(range, ':') == range) {
		*msg = "Invalid leading colon";
		rc = 1;
		return (rc);
	}

	len = strlen(range);
	if (range[len - 1] == ':') {
		*msg = "Invalid trailing colon";
		rc = 1;
		return (rc);
	}

	dup = strdup(range);
	s = strtok_r(dup, ":", &tmp);
	zor->zor_obj_start = strtoull(s, &p, 0);

	if (*p != '\0') {
		*msg = "Invalid characters in start object ID";
		rc = 1;
		goto out;
	}

	s = strtok_r(NULL, ":", &tmp);
	zor->zor_obj_end = strtoull(s, &p, 0);

	if (*p != '\0') {
		*msg = "Invalid characters in end object ID";
		rc = 1;
		goto out;
	}

	if (zor->zor_obj_start > zor->zor_obj_end) {
		*msg = "Start object ID may not exceed end object ID";
		rc = 1;
		goto out;
	}

	s = strtok_r(NULL, ":", &tmp);
	if (s == NULL) {
		zor->zor_flags = ZOR_FLAG_ALL_TYPES;
		goto out;
	} else if (strtok_r(NULL, ":", &tmp) != NULL) {
		*msg = "Invalid colon-delimited field after flags";
		rc = 1;
		goto out;
	}

	flagstr = s;
	for (i = 0; flagstr[i]; i++) {
		int bit;
		boolean_t negation = (flagstr[i] == '-');

		if (negation) {
			i++;
			if (flagstr[i] == '\0') {
				*msg = "Invalid trailing negation operator";
				rc = 1;
				goto out;
			}
		}
		bit = flagbits[(uchar_t)flagstr[i]];
		if (bit == 0) {
			*msg = "Invalid flag";
			rc = 1;
			goto out;
		}
		if (negation)
			flags &= ~bit;
		else
			flags |= bit;
	}
	zor->zor_flags = flags;

	zor->zor_obj_start = ZDB_MAP_OBJECT_ID(zor->zor_obj_start);
	zor->zor_obj_end = ZDB_MAP_OBJECT_ID(zor->zor_obj_end);

out:
	free(dup);
	return (rc);
}

static void
dump_objset(objset_t *os)
{
	dmu_objset_stats_t dds = { 0 };
	uint64_t object, object_count;
	uint64_t refdbytes, usedobjs, scratch;
	char numbuf[32];
	char blkbuf[BP_SPRINTF_LEN + 20];
	char osname[ZFS_MAX_DATASET_NAME_LEN];
	const char *type = "UNKNOWN";
	int verbosity = dump_opt['d'];
	boolean_t print_header;
	unsigned i;
	int error;
	uint64_t total_slots_used = 0;
	uint64_t max_slot_used = 0;
	uint64_t dnode_slots;
	uint64_t obj_start;
	uint64_t obj_end;
	uint64_t flags;

	/* make sure nicenum has enough space */
	_Static_assert(sizeof (numbuf) >= NN_NUMBUF_SZ, "numbuf truncated");

	dsl_pool_config_enter(dmu_objset_pool(os), FTAG);
	dmu_objset_fast_stat(os, &dds);
	dsl_pool_config_exit(dmu_objset_pool(os), FTAG);

	print_header = B_TRUE;

	if (dds.dds_type < DMU_OST_NUMTYPES)
		type = objset_types[dds.dds_type];

	if (dds.dds_type == DMU_OST_META) {
		dds.dds_creation_txg = TXG_INITIAL;
		usedobjs = BP_GET_FILL(os->os_rootbp);
		refdbytes = dsl_dir_phys(os->os_spa->spa_dsl_pool->dp_mos_dir)->
		    dd_used_bytes;
	} else {
		dmu_objset_space(os, &refdbytes, &scratch, &usedobjs, &scratch);
	}

	ASSERT3U(usedobjs, ==, BP_GET_FILL(os->os_rootbp));

	zdb_nicenum(refdbytes, numbuf, sizeof (numbuf));

	if (verbosity >= 4) {
		(void) snprintf(blkbuf, sizeof (blkbuf), ", rootbp ");
		(void) snprintf_blkptr(blkbuf + strlen(blkbuf),
		    sizeof (blkbuf) - strlen(blkbuf), os->os_rootbp);
	} else {
		blkbuf[0] = '\0';
	}

	dmu_objset_name(os, osname);

	(void) printf("Dataset %s [%s], ID %llu, cr_txg %llu, "
	    "%s, %llu objects%s%s\n",
	    osname, type, (u_longlong_t)dmu_objset_id(os),
	    (u_longlong_t)dds.dds_creation_txg,
	    numbuf, (u_longlong_t)usedobjs, blkbuf,
	    (dds.dds_inconsistent) ? " (inconsistent)" : "");

	for (i = 0; i < zopt_object_args; i++) {
		obj_start = zopt_object_ranges[i].zor_obj_start;
		obj_end = zopt_object_ranges[i].zor_obj_end;
		flags = zopt_object_ranges[i].zor_flags;

		object = obj_start;
		if (object == 0 || obj_start == obj_end)
			dump_object(os, object, verbosity, &print_header, NULL,
			    flags);
		else
			object--;

		while ((dmu_object_next(os, &object, B_FALSE, 0) == 0) &&
		    object <= obj_end) {
			dump_object(os, object, verbosity, &print_header, NULL,
			    flags);
		}
	}

	if (zopt_object_args > 0) {
		(void) printf("\n");
		return;
	}

	if (dump_opt['i'] != 0 || verbosity >= 2)
		dump_intent_log(dmu_objset_zil(os));

	if (dmu_objset_ds(os) != NULL) {
		dsl_dataset_t *ds = dmu_objset_ds(os);
		dump_blkptr_list(&ds->ds_deadlist, "Deadlist");
		if (dsl_deadlist_is_open(&ds->ds_dir->dd_livelist) &&
		    !dmu_objset_is_snapshot(os)) {
			dump_blkptr_list(&ds->ds_dir->dd_livelist, "Livelist");
			if (verify_dd_livelist(os) != 0)
				fatal("livelist is incorrect");
		}

		if (dsl_dataset_remap_deadlist_exists(ds)) {
			(void) printf("ds_remap_deadlist:\n");
			dump_blkptr_list(&ds->ds_remap_deadlist, "Deadlist");
		}
		count_ds_mos_objects(ds);
	}

	if (dmu_objset_ds(os) != NULL)
		dump_bookmarks(os, verbosity);

	if (verbosity < 2)
		return;

	if (BP_IS_HOLE(os->os_rootbp))
		return;

	dump_object(os, 0, verbosity, &print_header, NULL, 0);
	object_count = 0;
	if (DMU_USERUSED_DNODE(os) != NULL &&
	    DMU_USERUSED_DNODE(os)->dn_type != 0) {
		dump_object(os, DMU_USERUSED_OBJECT, verbosity, &print_header,
		    NULL, 0);
		dump_object(os, DMU_GROUPUSED_OBJECT, verbosity, &print_header,
		    NULL, 0);
	}

	if (DMU_PROJECTUSED_DNODE(os) != NULL &&
	    DMU_PROJECTUSED_DNODE(os)->dn_type != 0)
		dump_object(os, DMU_PROJECTUSED_OBJECT, verbosity,
		    &print_header, NULL, 0);

	object = 0;
	while ((error = dmu_object_next(os, &object, B_FALSE, 0)) == 0) {
		dump_object(os, object, verbosity, &print_header, &dnode_slots,
		    0);
		object_count++;
		total_slots_used += dnode_slots;
		max_slot_used = object + dnode_slots - 1;
	}

	(void) printf("\n");

	(void) printf("    Dnode slots:\n");
	(void) printf("\tTotal used:    %10llu\n",
	    (u_longlong_t)total_slots_used);
	(void) printf("\tMax used:      %10llu\n",
	    (u_longlong_t)max_slot_used);
	(void) printf("\tPercent empty: %10lf\n",
	    (double)(max_slot_used - total_slots_used)*100 /
	    (double)max_slot_used);
	(void) printf("\n");

	if (error != ESRCH) {
		(void) fprintf(stderr, "dmu_object_next() = %d\n", error);
		abort();
	}

	ASSERT3U(object_count, ==, usedobjs);

	if (leaked_objects != 0) {
		(void) printf("%d potentially leaked objects detected\n",
		    leaked_objects);
		leaked_objects = 0;
	}
}

static void
dump_uberblock(uberblock_t *ub, const char *header, const char *footer)
{
	time_t timestamp = ub->ub_timestamp;

	(void) printf("%s", header ? header : "");
	(void) printf("\tmagic = %016llx\n", (u_longlong_t)ub->ub_magic);
	(void) printf("\tversion = %llu\n", (u_longlong_t)ub->ub_version);
	(void) printf("\ttxg = %llu\n", (u_longlong_t)ub->ub_txg);
	(void) printf("\tguid_sum = %llu\n", (u_longlong_t)ub->ub_guid_sum);
	(void) printf("\ttimestamp = %llu UTC = %s",
	    (u_longlong_t)ub->ub_timestamp, ctime(&timestamp));

	char blkbuf[BP_SPRINTF_LEN];
	snprintf_blkptr(blkbuf, sizeof (blkbuf), &ub->ub_rootbp);
	(void) printf("\tbp = %s\n", blkbuf);

	(void) printf("\tmmp_magic = %016llx\n",
	    (u_longlong_t)ub->ub_mmp_magic);
	if (MMP_VALID(ub)) {
		(void) printf("\tmmp_delay = %0llu\n",
		    (u_longlong_t)ub->ub_mmp_delay);
		if (MMP_SEQ_VALID(ub))
			(void) printf("\tmmp_seq = %u\n",
			    (unsigned int) MMP_SEQ(ub));
		if (MMP_FAIL_INT_VALID(ub))
			(void) printf("\tmmp_fail = %u\n",
			    (unsigned int) MMP_FAIL_INT(ub));
		if (MMP_INTERVAL_VALID(ub))
			(void) printf("\tmmp_write = %u\n",
			    (unsigned int) MMP_INTERVAL(ub));
		/* After MMP_* to make summarize_uberblock_mmp cleaner */
		(void) printf("\tmmp_valid = %x\n",
		    (unsigned int) ub->ub_mmp_config & 0xFF);
	}

	if (dump_opt['u'] >= 4) {
		char blkbuf[BP_SPRINTF_LEN];
		snprintf_blkptr(blkbuf, sizeof (blkbuf), &ub->ub_rootbp);
		(void) printf("\trootbp = %s\n", blkbuf);
	}
	(void) printf("\tcheckpoint_txg = %llu\n",
	    (u_longlong_t)ub->ub_checkpoint_txg);

	(void) printf("\traidz_reflow state=%u off=%llu\n",
	    (int)RRSS_GET_STATE(ub),
	    (u_longlong_t)RRSS_GET_OFFSET(ub));

	(void) printf("%s", footer ? footer : "");
}

static void
dump_config(spa_t *spa)
{
	dmu_buf_t *db;
	size_t nvsize = 0;
	int error = 0;


	error = dmu_bonus_hold(spa->spa_meta_objset,
	    spa->spa_config_object, FTAG, &db);

	if (error == 0) {
		nvsize = *(uint64_t *)db->db_data;
		dmu_buf_rele(db, FTAG);

		(void) printf("\nMOS Configuration:\n");
		dump_packed_nvlist(spa->spa_meta_objset,
		    spa->spa_config_object, (void *)&nvsize, 1);
	} else {
		(void) fprintf(stderr, "dmu_bonus_hold(%llu) failed, errno %d",
		    (u_longlong_t)spa->spa_config_object, error);
	}
}

static void
dump_cachefile(const char *cachefile)
{
	int fd;
	struct stat64 statbuf;
	char *buf;
	nvlist_t *config;

	if ((fd = open64(cachefile, O_RDONLY)) < 0) {
		(void) printf("cannot open '%s': %s\n", cachefile,
		    strerror(errno));
		zdb_exit(1);
	}

	if (fstat64(fd, &statbuf) != 0) {
		(void) printf("failed to stat '%s': %s\n", cachefile,
		    strerror(errno));
		zdb_exit(1);
	}

	if ((buf = malloc(statbuf.st_size)) == NULL) {
		(void) fprintf(stderr, "failed to allocate %llu bytes\n",
		    (u_longlong_t)statbuf.st_size);
		zdb_exit(1);
	}

	if (read(fd, buf, statbuf.st_size) != statbuf.st_size) {
		(void) fprintf(stderr, "failed to read %llu bytes\n",
		    (u_longlong_t)statbuf.st_size);
		zdb_exit(1);
	}

	(void) close(fd);

	if (nvlist_unpack(buf, statbuf.st_size, &config, 0) != 0) {
		(void) fprintf(stderr, "failed to unpack nvlist\n");
		zdb_exit(1);
	}

	free(buf);

	dump_nvlist(config, 0);

	nvlist_free(config);
}

/*
 * ZFS label nvlist stats
 */
typedef struct zdb_nvl_stats {
	int		zns_list_count;
	int		zns_leaf_count;
	size_t		zns_leaf_largest;
	size_t		zns_leaf_total;
	nvlist_t	*zns_string;
	nvlist_t	*zns_uint64;
	nvlist_t	*zns_boolean;
} zdb_nvl_stats_t;

static void
collect_nvlist_stats(nvlist_t *nvl, zdb_nvl_stats_t *stats)
{
	nvlist_t *list, **array;
	nvpair_t *nvp = NULL;
	const char *name;
	uint_t i, items;

	stats->zns_list_count++;

	while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) {
		name = nvpair_name(nvp);

		switch (nvpair_type(nvp)) {
		case DATA_TYPE_STRING:
			fnvlist_add_string(stats->zns_string, name,
			    fnvpair_value_string(nvp));
			break;
		case DATA_TYPE_UINT64:
			fnvlist_add_uint64(stats->zns_uint64, name,
			    fnvpair_value_uint64(nvp));
			break;
		case DATA_TYPE_BOOLEAN:
			fnvlist_add_boolean(stats->zns_boolean, name);
			break;
		case DATA_TYPE_NVLIST:
			if (nvpair_value_nvlist(nvp, &list) == 0)
				collect_nvlist_stats(list, stats);
			break;
		case DATA_TYPE_NVLIST_ARRAY:
			if (nvpair_value_nvlist_array(nvp, &array, &items) != 0)
				break;

			for (i = 0; i < items; i++) {
				collect_nvlist_stats(array[i], stats);

				/* collect stats on leaf vdev */
				if (strcmp(name, "children") == 0) {
					size_t size;

					(void) nvlist_size(array[i], &size,
					    NV_ENCODE_XDR);
					stats->zns_leaf_total += size;
					if (size > stats->zns_leaf_largest)
						stats->zns_leaf_largest = size;
					stats->zns_leaf_count++;
				}
			}
			break;
		default:
			(void) printf("skip type %d!\n", (int)nvpair_type(nvp));
		}
	}
}

static void
dump_nvlist_stats(nvlist_t *nvl, size_t cap)
{
	zdb_nvl_stats_t stats = { 0 };
	size_t size, sum = 0, total;
	size_t noise;

	/* requires nvlist with non-unique names for stat collection */
	VERIFY0(nvlist_alloc(&stats.zns_string, 0, 0));
	VERIFY0(nvlist_alloc(&stats.zns_uint64, 0, 0));
	VERIFY0(nvlist_alloc(&stats.zns_boolean, 0, 0));
	VERIFY0(nvlist_size(stats.zns_boolean, &noise, NV_ENCODE_XDR));

	(void) printf("\n\nZFS Label NVList Config Stats:\n");

	VERIFY0(nvlist_size(nvl, &total, NV_ENCODE_XDR));
	(void) printf("  %d bytes used, %d bytes free (using %4.1f%%)\n\n",
	    (int)total, (int)(cap - total), 100.0 * total / cap);

	collect_nvlist_stats(nvl, &stats);

	VERIFY0(nvlist_size(stats.zns_uint64, &size, NV_ENCODE_XDR));
	size -= noise;
	sum += size;
	(void) printf("%12s %4d %6d bytes (%5.2f%%)\n", "integers:",
	    (int)fnvlist_num_pairs(stats.zns_uint64),
	    (int)size, 100.0 * size / total);

	VERIFY0(nvlist_size(stats.zns_string, &size, NV_ENCODE_XDR));
	size -= noise;
	sum += size;
	(void) printf("%12s %4d %6d bytes (%5.2f%%)\n", "strings:",
	    (int)fnvlist_num_pairs(stats.zns_string),
	    (int)size, 100.0 * size / total);

	VERIFY0(nvlist_size(stats.zns_boolean, &size, NV_ENCODE_XDR));
	size -= noise;
	sum += size;
	(void) printf("%12s %4d %6d bytes (%5.2f%%)\n", "booleans:",
	    (int)fnvlist_num_pairs(stats.zns_boolean),
	    (int)size, 100.0 * size / total);

	size = total - sum;	/* treat remainder as nvlist overhead */
	(void) printf("%12s %4d %6d bytes (%5.2f%%)\n\n", "nvlists:",
	    stats.zns_list_count, (int)size, 100.0 * size / total);

	if (stats.zns_leaf_count > 0) {
		size_t average = stats.zns_leaf_total / stats.zns_leaf_count;

		(void) printf("%12s %4d %6d bytes average\n", "leaf vdevs:",
		    stats.zns_leaf_count, (int)average);
		(void) printf("%24d bytes largest\n",
		    (int)stats.zns_leaf_largest);

		if (dump_opt['l'] >= 3 && average > 0)
			(void) printf("  space for %d additional leaf vdevs\n",
			    (int)((cap - total) / average));
	}
	(void) printf("\n");

	nvlist_free(stats.zns_string);
	nvlist_free(stats.zns_uint64);
	nvlist_free(stats.zns_boolean);
}

typedef struct cksum_record {
	zio_cksum_t cksum;
	boolean_t labels[VDEV_LABELS];
	avl_node_t link;
} cksum_record_t;

static int
cksum_record_compare(const void *x1, const void *x2)
{
	const cksum_record_t *l = (cksum_record_t *)x1;
	const cksum_record_t *r = (cksum_record_t *)x2;
	int arraysize = ARRAY_SIZE(l->cksum.zc_word);
	int difference = 0;

	for (int i = 0; i < arraysize; i++) {
		difference = TREE_CMP(l->cksum.zc_word[i], r->cksum.zc_word[i]);
		if (difference)
			break;
	}

	return (difference);
}

static cksum_record_t *
cksum_record_alloc(zio_cksum_t *cksum, int l)
{
	cksum_record_t *rec;

	rec = umem_zalloc(sizeof (*rec), UMEM_NOFAIL);
	rec->cksum = *cksum;
	rec->labels[l] = B_TRUE;

	return (rec);
}

static cksum_record_t *
cksum_record_lookup(avl_tree_t *tree, zio_cksum_t *cksum)
{
	cksum_record_t lookup = { .cksum = *cksum };
	avl_index_t where;

	return (avl_find(tree, &lookup, &where));
}

static cksum_record_t *
cksum_record_insert(avl_tree_t *tree, zio_cksum_t *cksum, int l)
{
	cksum_record_t *rec;

	rec = cksum_record_lookup(tree, cksum);
	if (rec) {
		rec->labels[l] = B_TRUE;
	} else {
		rec = cksum_record_alloc(cksum, l);
		avl_add(tree, rec);
	}

	return (rec);
}

static int
first_label(cksum_record_t *rec)
{
	for (int i = 0; i < VDEV_LABELS; i++)
		if (rec->labels[i])
			return (i);

	return (-1);
}

static void
print_label_numbers(const char *prefix, const cksum_record_t *rec)
{
	fputs(prefix, stdout);
	for (int i = 0; i < VDEV_LABELS; i++)
		if (rec->labels[i] == B_TRUE)
			printf("%d ", i);
	putchar('\n');
}

#define	MAX_UBERBLOCK_COUNT (VDEV_UBERBLOCK_RING >> UBERBLOCK_SHIFT)

typedef struct zdb_label {
	vdev_label_t label;
	uint64_t label_offset;
	nvlist_t *config_nv;
	cksum_record_t *config;
	cksum_record_t *uberblocks[MAX_UBERBLOCK_COUNT];
	boolean_t header_printed;
	boolean_t read_failed;
	boolean_t cksum_valid;
} zdb_label_t;

static void
print_label_header(zdb_label_t *label, int l)
{

	if (dump_opt['q'])
		return;

	if (label->header_printed == B_TRUE)
		return;

	(void) printf("------------------------------------\n");
	(void) printf("LABEL %d %s\n", l,
	    label->cksum_valid ? "" : "(Bad label cksum)");
	(void) printf("------------------------------------\n");

	label->header_printed = B_TRUE;
}

static void
print_l2arc_header(void)
{
	(void) printf("------------------------------------\n");
	(void) printf("L2ARC device header\n");
	(void) printf("------------------------------------\n");
}

static void
print_l2arc_log_blocks(void)
{
	(void) printf("------------------------------------\n");
	(void) printf("L2ARC device log blocks\n");
	(void) printf("------------------------------------\n");
}

static void
dump_l2arc_log_entries(uint64_t log_entries,
    l2arc_log_ent_phys_t *le, uint64_t i)
{
	for (int j = 0; j < log_entries; j++) {
		dva_t dva = le[j].le_dva;
		(void) printf("lb[%4llu]\tle[%4d]\tDVA asize: %llu, "
		    "vdev: %llu, offset: %llu\n",
		    (u_longlong_t)i, j + 1,
		    (u_longlong_t)DVA_GET_ASIZE(&dva),
		    (u_longlong_t)DVA_GET_VDEV(&dva),
		    (u_longlong_t)DVA_GET_OFFSET(&dva));
		(void) printf("|\t\t\t\tbirth: %llu\n",
		    (u_longlong_t)le[j].le_birth);
		(void) printf("|\t\t\t\tlsize: %llu\n",
		    (u_longlong_t)L2BLK_GET_LSIZE((&le[j])->le_prop));
		(void) printf("|\t\t\t\tpsize: %llu\n",
		    (u_longlong_t)L2BLK_GET_PSIZE((&le[j])->le_prop));
		(void) printf("|\t\t\t\tcompr: %llu\n",
		    (u_longlong_t)L2BLK_GET_COMPRESS((&le[j])->le_prop));
		(void) printf("|\t\t\t\tcomplevel: %llu\n",
		    (u_longlong_t)(&le[j])->le_complevel);
		(void) printf("|\t\t\t\ttype: %llu\n",
		    (u_longlong_t)L2BLK_GET_TYPE((&le[j])->le_prop));
		(void) printf("|\t\t\t\tprotected: %llu\n",
		    (u_longlong_t)L2BLK_GET_PROTECTED((&le[j])->le_prop));
		(void) printf("|\t\t\t\tprefetch: %llu\n",
		    (u_longlong_t)L2BLK_GET_PREFETCH((&le[j])->le_prop));
		(void) printf("|\t\t\t\taddress: %llu\n",
		    (u_longlong_t)le[j].le_daddr);
		(void) printf("|\t\t\t\tARC state: %llu\n",
		    (u_longlong_t)L2BLK_GET_STATE((&le[j])->le_prop));
		(void) printf("|\n");
	}
	(void) printf("\n");
}

static void
dump_l2arc_log_blkptr(const l2arc_log_blkptr_t *lbps)
{
	(void) printf("|\t\tdaddr: %llu\n", (u_longlong_t)lbps->lbp_daddr);
	(void) printf("|\t\tpayload_asize: %llu\n",
	    (u_longlong_t)lbps->lbp_payload_asize);
	(void) printf("|\t\tpayload_start: %llu\n",
	    (u_longlong_t)lbps->lbp_payload_start);
	(void) printf("|\t\tlsize: %llu\n",
	    (u_longlong_t)L2BLK_GET_LSIZE(lbps->lbp_prop));
	(void) printf("|\t\tasize: %llu\n",
	    (u_longlong_t)L2BLK_GET_PSIZE(lbps->lbp_prop));
	(void) printf("|\t\tcompralgo: %llu\n",
	    (u_longlong_t)L2BLK_GET_COMPRESS(lbps->lbp_prop));
	(void) printf("|\t\tcksumalgo: %llu\n",
	    (u_longlong_t)L2BLK_GET_CHECKSUM(lbps->lbp_prop));
	(void) printf("|\n\n");
}

static void
dump_l2arc_log_blocks(int fd, const l2arc_dev_hdr_phys_t *l2dhdr,
    l2arc_dev_hdr_phys_t *rebuild)
{
	l2arc_log_blk_phys_t this_lb;
	uint64_t asize;
	l2arc_log_blkptr_t lbps[2];
	zio_cksum_t cksum;
	int failed = 0;
	l2arc_dev_t dev;

	if (!dump_opt['q'])
		print_l2arc_log_blocks();
	memcpy(lbps, l2dhdr->dh_start_lbps, sizeof (lbps));

	dev.l2ad_evict = l2dhdr->dh_evict;
	dev.l2ad_start = l2dhdr->dh_start;
	dev.l2ad_end = l2dhdr->dh_end;

	if (l2dhdr->dh_start_lbps[0].lbp_daddr == 0) {
		/* no log blocks to read */
		if (!dump_opt['q']) {
			(void) printf("No log blocks to read\n");
			(void) printf("\n");
		}
		return;
	} else {
		dev.l2ad_hand = lbps[0].lbp_daddr +
		    L2BLK_GET_PSIZE((&lbps[0])->lbp_prop);
	}

	dev.l2ad_first = !!(l2dhdr->dh_flags & L2ARC_DEV_HDR_EVICT_FIRST);

	for (;;) {
		if (!l2arc_log_blkptr_valid(&dev, &lbps[0]))
			break;

		/* L2BLK_GET_PSIZE returns aligned size for log blocks */
		asize = L2BLK_GET_PSIZE((&lbps[0])->lbp_prop);
		if (pread64(fd, &this_lb, asize, lbps[0].lbp_daddr) != asize) {
			if (!dump_opt['q']) {
				(void) printf("Error while reading next log "
				    "block\n\n");
			}
			break;
		}

		fletcher_4_native_varsize(&this_lb, asize, &cksum);
		if (!ZIO_CHECKSUM_EQUAL(cksum, lbps[0].lbp_cksum)) {
			failed++;
			if (!dump_opt['q']) {
				(void) printf("Invalid cksum\n");
				dump_l2arc_log_blkptr(&lbps[0]);
			}
			break;
		}

		switch (L2BLK_GET_COMPRESS((&lbps[0])->lbp_prop)) {
		case ZIO_COMPRESS_OFF:
			break;
		default: {
			abd_t *abd = abd_alloc_linear(asize, B_TRUE);
			abd_copy_from_buf_off(abd, &this_lb, 0, asize);
			abd_t dabd;
			abd_get_from_buf_struct(&dabd, &this_lb,
			    sizeof (this_lb));
			int err = zio_decompress_data(L2BLK_GET_COMPRESS(
			    (&lbps[0])->lbp_prop), abd, &dabd,
			    asize, sizeof (this_lb), NULL);
			abd_free(&dabd);
			abd_free(abd);
			if (err != 0) {
				(void) printf("L2ARC block decompression "
				    "failed\n");
				goto out;
			}
			break;
		}
		}

		if (this_lb.lb_magic == BSWAP_64(L2ARC_LOG_BLK_MAGIC))
			byteswap_uint64_array(&this_lb, sizeof (this_lb));
		if (this_lb.lb_magic != L2ARC_LOG_BLK_MAGIC) {
			if (!dump_opt['q'])
				(void) printf("Invalid log block magic\n\n");
			break;
		}

		rebuild->dh_lb_count++;
		rebuild->dh_lb_asize += asize;
		if (dump_opt['l'] > 1 && !dump_opt['q']) {
			(void) printf("lb[%4llu]\tmagic: %llu\n",
			    (u_longlong_t)rebuild->dh_lb_count,
			    (u_longlong_t)this_lb.lb_magic);
			dump_l2arc_log_blkptr(&lbps[0]);
		}

		if (dump_opt['l'] > 2 && !dump_opt['q'])
			dump_l2arc_log_entries(l2dhdr->dh_log_entries,
			    this_lb.lb_entries,
			    rebuild->dh_lb_count);

		if (l2arc_range_check_overlap(lbps[1].lbp_payload_start,
		    lbps[0].lbp_payload_start, dev.l2ad_evict) &&
		    !dev.l2ad_first)
			break;

		lbps[0] = lbps[1];
		lbps[1] = this_lb.lb_prev_lbp;
	}
out:
	if (!dump_opt['q']) {
		(void) printf("log_blk_count:\t %llu with valid cksum\n",
		    (u_longlong_t)rebuild->dh_lb_count);
		(void) printf("\t\t %d with invalid cksum\n", failed);
		(void) printf("log_blk_asize:\t %llu\n\n",
		    (u_longlong_t)rebuild->dh_lb_asize);
	}
}

static int
dump_l2arc_header(int fd)
{
	l2arc_dev_hdr_phys_t l2dhdr = {0}, rebuild = {0};
	int error = B_FALSE;

	if (pread64(fd, &l2dhdr, sizeof (l2dhdr),
	    VDEV_LABEL_START_SIZE) != sizeof (l2dhdr)) {
		error = B_TRUE;
	} else {
		if (l2dhdr.dh_magic == BSWAP_64(L2ARC_DEV_HDR_MAGIC))
			byteswap_uint64_array(&l2dhdr, sizeof (l2dhdr));

		if (l2dhdr.dh_magic != L2ARC_DEV_HDR_MAGIC)
			error = B_TRUE;
	}

	if (error) {
		(void) printf("L2ARC device header not found\n\n");
		/* Do not return an error here for backward compatibility */
		return (0);
	} else if (!dump_opt['q']) {
		print_l2arc_header();

		(void) printf("    magic: %llu\n",
		    (u_longlong_t)l2dhdr.dh_magic);
		(void) printf("    version: %llu\n",
		    (u_longlong_t)l2dhdr.dh_version);
		(void) printf("    pool_guid: %llu\n",
		    (u_longlong_t)l2dhdr.dh_spa_guid);
		(void) printf("    flags: %llu\n",
		    (u_longlong_t)l2dhdr.dh_flags);
		(void) printf("    start_lbps[0]: %llu\n",
		    (u_longlong_t)
		    l2dhdr.dh_start_lbps[0].lbp_daddr);
		(void) printf("    start_lbps[1]: %llu\n",
		    (u_longlong_t)
		    l2dhdr.dh_start_lbps[1].lbp_daddr);
		(void) printf("    log_blk_ent: %llu\n",
		    (u_longlong_t)l2dhdr.dh_log_entries);
		(void) printf("    start: %llu\n",
		    (u_longlong_t)l2dhdr.dh_start);
		(void) printf("    end: %llu\n",
		    (u_longlong_t)l2dhdr.dh_end);
		(void) printf("    evict: %llu\n",
		    (u_longlong_t)l2dhdr.dh_evict);
		(void) printf("    lb_asize_refcount: %llu\n",
		    (u_longlong_t)l2dhdr.dh_lb_asize);
		(void) printf("    lb_count_refcount: %llu\n",
		    (u_longlong_t)l2dhdr.dh_lb_count);
		(void) printf("    trim_action_time: %llu\n",
		    (u_longlong_t)l2dhdr.dh_trim_action_time);
		(void) printf("    trim_state: %llu\n\n",
		    (u_longlong_t)l2dhdr.dh_trim_state);
	}

	dump_l2arc_log_blocks(fd, &l2dhdr, &rebuild);
	/*
	 * The total aligned size of log blocks and the number of log blocks
	 * reported in the header of the device may be less than what zdb
	 * reports by dump_l2arc_log_blocks() which emulates l2arc_rebuild().
	 * This happens because dump_l2arc_log_blocks() lacks the memory
	 * pressure valve that l2arc_rebuild() has. Thus, if we are on a system
	 * with low memory, l2arc_rebuild will exit prematurely and dh_lb_asize
	 * and dh_lb_count will be lower to begin with than what exists on the
	 * device. This is normal and zdb should not exit with an error. The
	 * opposite case should never happen though, the values reported in the
	 * header should never be higher than what dump_l2arc_log_blocks() and
	 * l2arc_rebuild() report. If this happens there is a leak in the
	 * accounting of log blocks.
	 */
	if (l2dhdr.dh_lb_asize > rebuild.dh_lb_asize ||
	    l2dhdr.dh_lb_count > rebuild.dh_lb_count)
		return (1);

	return (0);
}

static void
dump_config_from_label(zdb_label_t *label, size_t buflen, int l)
{
	if (dump_opt['q'])
		return;

	if ((dump_opt['l'] < 3) && (first_label(label->config) != l))
		return;

	print_label_header(label, l);
	dump_nvlist(label->config_nv, 4);
	print_label_numbers("    labels = ", label->config);

	if (dump_opt['l'] >= 2)
		dump_nvlist_stats(label->config_nv, buflen);
}

#define	ZDB_MAX_UB_HEADER_SIZE 32

static void
dump_label_uberblocks(zdb_label_t *label, uint64_t ashift, int label_num)
{

	vdev_t vd;
	char header[ZDB_MAX_UB_HEADER_SIZE];

	vd.vdev_ashift = ashift;
	vd.vdev_top = &vd;

	for (int i = 0; i < VDEV_UBERBLOCK_COUNT(&vd); i++) {
		uint64_t uoff = VDEV_UBERBLOCK_OFFSET(&vd, i);
		uberblock_t *ub = (void *)((char *)&label->label + uoff);
		cksum_record_t *rec = label->uberblocks[i];

		if (rec == NULL) {
			if (dump_opt['u'] >= 2) {
				print_label_header(label, label_num);
				(void) printf("    Uberblock[%d] invalid\n", i);
			}
			continue;
		}

		if ((dump_opt['u'] < 3) && (first_label(rec) != label_num))
			continue;

		if ((dump_opt['u'] < 4) &&
		    (ub->ub_mmp_magic == MMP_MAGIC) && ub->ub_mmp_delay &&
		    (i >= VDEV_UBERBLOCK_COUNT(&vd) - MMP_BLOCKS_PER_LABEL))
			continue;

		print_label_header(label, label_num);
		(void) snprintf(header, ZDB_MAX_UB_HEADER_SIZE,
		    "    Uberblock[%d]\n", i);
		dump_uberblock(ub, header, "");
		print_label_numbers("        labels = ", rec);
	}
}

static char curpath[PATH_MAX];

/*
 * Iterate through the path components, recursively passing
 * current one's obj and remaining path until we find the obj
 * for the last one.
 */
static int
dump_path_impl(objset_t *os, uint64_t obj, char *name, uint64_t *retobj)
{
	int err;
	boolean_t header = B_TRUE;
	uint64_t child_obj;
	char *s;
	dmu_buf_t *db;
	dmu_object_info_t doi;

	if ((s = strchr(name, '/')) != NULL)
		*s = '\0';
	err = zap_lookup(os, obj, name, 8, 1, &child_obj);

	(void) strlcat(curpath, name, sizeof (curpath));

	if (err != 0) {
		(void) fprintf(stderr, "failed to lookup %s: %s\n",
		    curpath, strerror(err));
		return (err);
	}

	child_obj = ZFS_DIRENT_OBJ(child_obj);
	err = sa_buf_hold(os, child_obj, FTAG, &db);
	if (err != 0) {
		(void) fprintf(stderr,
		    "failed to get SA dbuf for obj %llu: %s\n",
		    (u_longlong_t)child_obj, strerror(err));
		return (EINVAL);
	}
	dmu_object_info_from_db(db, &doi);
	sa_buf_rele(db, FTAG);

	if (doi.doi_bonus_type != DMU_OT_SA &&
	    doi.doi_bonus_type != DMU_OT_ZNODE) {
		(void) fprintf(stderr, "invalid bonus type %d for obj %llu\n",
		    doi.doi_bonus_type, (u_longlong_t)child_obj);
		return (EINVAL);
	}

	if (dump_opt['v'] > 6) {
		(void) printf("obj=%llu %s type=%d bonustype=%d\n",
		    (u_longlong_t)child_obj, curpath, doi.doi_type,
		    doi.doi_bonus_type);
	}

	(void) strlcat(curpath, "/", sizeof (curpath));

	switch (doi.doi_type) {
	case DMU_OT_DIRECTORY_CONTENTS:
		if (s != NULL && *(s + 1) != '\0')
			return (dump_path_impl(os, child_obj, s + 1, retobj));
		zfs_fallthrough;
	case DMU_OT_PLAIN_FILE_CONTENTS:
		if (retobj != NULL) {
			*retobj = child_obj;
		} else {
			dump_object(os, child_obj, dump_opt['v'], &header,
			    NULL, 0);
		}
		return (0);
	default:
		(void) fprintf(stderr, "object %llu has non-file/directory "
		    "type %d\n", (u_longlong_t)obj, doi.doi_type);
		break;
	}

	return (EINVAL);
}

/*
 * Dump the blocks for the object specified by path inside the dataset.
 */
static int
dump_path(char *ds, char *path, uint64_t *retobj)
{
	int err;
	objset_t *os;
	uint64_t root_obj;

	err = open_objset(ds, FTAG, &os);
	if (err != 0)
		return (err);

	err = zap_lookup(os, MASTER_NODE_OBJ, ZFS_ROOT_OBJ, 8, 1, &root_obj);
	if (err != 0) {
		(void) fprintf(stderr, "can't lookup root znode: %s\n",
		    strerror(err));
		close_objset(os, FTAG);
		return (EINVAL);
	}

	(void) snprintf(curpath, sizeof (curpath), "dataset=%s path=/", ds);

	err = dump_path_impl(os, root_obj, path, retobj);

	close_objset(os, FTAG);
	return (err);
}

static int
dump_backup_bytes(objset_t *os, void *buf, int len, void *arg)
{
	const char *p = (const char *)buf;
	ssize_t nwritten;

	(void) os;
	(void) arg;

	/* Write the data out, handling short writes and signals. */
	while ((nwritten = write(STDOUT_FILENO, p, len)) < len) {
		if (nwritten < 0) {
			if (errno == EINTR)
				continue;
			return (errno);
		}
		p += nwritten;
		len -= nwritten;
	}

	return (0);
}

static void
dump_backup(const char *pool, uint64_t objset_id, const char *flagstr)
{
	boolean_t embed = B_FALSE;
	boolean_t large_block = B_FALSE;
	boolean_t compress = B_FALSE;
	boolean_t raw = B_FALSE;

	const char *c;
	for (c = flagstr; c != NULL && *c != '\0'; c++) {
		switch (*c) {
			case 'e':
				embed = B_TRUE;
				break;
			case 'L':
				large_block = B_TRUE;
				break;
			case 'c':
				compress = B_TRUE;
				break;
			case 'w':
				raw = B_TRUE;
				break;
			default:
				fprintf(stderr, "dump_backup: invalid flag "
				    "'%c'\n", *c);
				return;
		}
	}

	if (isatty(STDOUT_FILENO)) {
		fprintf(stderr, "dump_backup: stream cannot be written "
		    "to a terminal\n");
		return;
	}

	offset_t off = 0;
	dmu_send_outparams_t out = {
	    .dso_outfunc = dump_backup_bytes,
	    .dso_dryrun  = B_FALSE,
	};

	int err = dmu_send_obj(pool, objset_id, /* fromsnap */0, embed,
	    large_block, compress, raw, /* saved */ B_FALSE, STDOUT_FILENO,
	    &off, &out);
	if (err != 0) {
		fprintf(stderr, "dump_backup: dmu_send_obj: %s\n",
		    strerror(err));
		return;
	}
}

static int
zdb_copy_object(objset_t *os, uint64_t srcobj, char *destfile)
{
	int err = 0;
	uint64_t size, readsize, oursize, offset;
	ssize_t writesize;
	sa_handle_t *hdl;

	(void) printf("Copying object %" PRIu64 " to file %s\n", srcobj,
	    destfile);

	VERIFY3P(os, ==, sa_os);
	if ((err = sa_handle_get(os, srcobj, NULL, SA_HDL_PRIVATE, &hdl))) {
		(void) printf("Failed to get handle for SA znode\n");
		return (err);
	}
	if ((err = sa_lookup(hdl, sa_attr_table[ZPL_SIZE], &size, 8))) {
		(void) sa_handle_destroy(hdl);
		return (err);
	}
	(void) sa_handle_destroy(hdl);

	(void) printf("Object %" PRIu64 " is %" PRIu64 " bytes\n", srcobj,
	    size);
	if (size == 0) {
		return (EINVAL);
	}

	int fd = open(destfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
	if (fd == -1)
		return (errno);
	/*
	 * We cap the size at 1 mebibyte here to prevent
	 * allocation failures and nigh-infinite printing if the
	 * object is extremely large.
	 */
	oursize = MIN(size, 1 << 20);
	offset = 0;
	char *buf = kmem_alloc(oursize, KM_NOSLEEP);
	if (buf == NULL) {
		(void) close(fd);
		return (ENOMEM);
	}

	while (offset < size) {
		readsize = MIN(size - offset, 1 << 20);
		err = dmu_read(os, srcobj, offset, readsize, buf, 0);
		if (err != 0) {
			(void) printf("got error %u from dmu_read\n", err);
			kmem_free(buf, oursize);
			(void) close(fd);
			return (err);
		}
		if (dump_opt['v'] > 3) {
			(void) printf("Read offset=%" PRIu64 " size=%" PRIu64
			    " error=%d\n", offset, readsize, err);
		}

		writesize = write(fd, buf, readsize);
		if (writesize < 0) {
			err = errno;
			break;
		} else if (writesize != readsize) {
			/* Incomplete write */
			(void) fprintf(stderr, "Short write, only wrote %llu of"
			    " %" PRIu64 " bytes, exiting...\n",
			    (u_longlong_t)writesize, readsize);
			break;
		}

		offset += readsize;
	}

	(void) close(fd);

	if (buf != NULL)
		kmem_free(buf, oursize);

	return (err);
}

static boolean_t
label_cksum_valid(vdev_label_t *label, uint64_t offset)
{
	zio_checksum_info_t *ci = &zio_checksum_table[ZIO_CHECKSUM_LABEL];
	zio_cksum_t expected_cksum;
	zio_cksum_t actual_cksum;
	zio_cksum_t verifier;
	zio_eck_t *eck;
	int byteswap;

	void *data = (char *)label + offsetof(vdev_label_t, vl_vdev_phys);
	eck = (zio_eck_t *)((char *)(data) + VDEV_PHYS_SIZE) - 1;

	offset += offsetof(vdev_label_t, vl_vdev_phys);
	ZIO_SET_CHECKSUM(&verifier, offset, 0, 0, 0);

	byteswap = (eck->zec_magic == BSWAP_64(ZEC_MAGIC));
	if (byteswap)
		byteswap_uint64_array(&verifier, sizeof (zio_cksum_t));

	expected_cksum = eck->zec_cksum;
	eck->zec_cksum = verifier;

	abd_t *abd = abd_get_from_buf(data, VDEV_PHYS_SIZE);
	ci->ci_func[byteswap](abd, VDEV_PHYS_SIZE, NULL, &actual_cksum);
	abd_free(abd);

	if (byteswap)
		byteswap_uint64_array(&expected_cksum, sizeof (zio_cksum_t));

	if (ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum))
		return (B_TRUE);

	return (B_FALSE);
}

static int
dump_label(const char *dev)
{
	char path[MAXPATHLEN];
	zdb_label_t labels[VDEV_LABELS] = {{{{0}}}};
	uint64_t psize, ashift, l2cache;
	struct stat64 statbuf;
	boolean_t config_found = B_FALSE;
	boolean_t error = B_FALSE;
	boolean_t read_l2arc_header = B_FALSE;
	avl_tree_t config_tree;
	avl_tree_t uberblock_tree;
	void *node, *cookie;
	int fd;

	/*
	 * Check if we were given absolute path and use it as is.
	 * Otherwise if the provided vdev name doesn't point to a file,
	 * try prepending expected disk paths and partition numbers.
	 */
	(void) strlcpy(path, dev, sizeof (path));
	if (dev[0] != '/' && stat64(path, &statbuf) != 0) {
		int error;

		error = zfs_resolve_shortname(dev, path, MAXPATHLEN);
		if (error == 0 && zfs_dev_is_whole_disk(path)) {
			if (zfs_append_partition(path, MAXPATHLEN) == -1)
				error = ENOENT;
		}

		if (error || (stat64(path, &statbuf) != 0)) {
			(void) printf("failed to find device %s, try "
			    "specifying absolute path instead\n", dev);
			return (1);
		}
	}

	if ((fd = open64(path, O_RDONLY)) < 0) {
		(void) printf("cannot open '%s': %s\n", path, strerror(errno));
		zdb_exit(1);
	}

	if (fstat64_blk(fd, &statbuf) != 0) {
		(void) printf("failed to stat '%s': %s\n", path,
		    strerror(errno));
		(void) close(fd);
		zdb_exit(1);
	}

	if (S_ISBLK(statbuf.st_mode) && zfs_dev_flush(fd) != 0)
		(void) printf("failed to invalidate cache '%s' : %s\n", path,
		    strerror(errno));

	avl_create(&config_tree, cksum_record_compare,
	    sizeof (cksum_record_t), offsetof(cksum_record_t, link));
	avl_create(&uberblock_tree, cksum_record_compare,
	    sizeof (cksum_record_t), offsetof(cksum_record_t, link));

	psize = statbuf.st_size;
	psize = P2ALIGN_TYPED(psize, sizeof (vdev_label_t), uint64_t);
	ashift = SPA_MINBLOCKSHIFT;

	/*
	 * 1. Read the label from disk
	 * 2. Verify label cksum
	 * 3. Unpack the configuration and insert in config tree.
	 * 4. Traverse all uberblocks and insert in uberblock tree.
	 */
	for (int l = 0; l < VDEV_LABELS; l++) {
		zdb_label_t *label = &labels[l];
		char *buf = label->label.vl_vdev_phys.vp_nvlist;
		size_t buflen = sizeof (label->label.vl_vdev_phys.vp_nvlist);
		nvlist_t *config;
		cksum_record_t *rec;
		zio_cksum_t cksum;
		vdev_t vd;

		label->label_offset = vdev_label_offset(psize, l, 0);

		if (pread64(fd, &label->label, sizeof (label->label),
		    label->label_offset) != sizeof (label->label)) {
			if (!dump_opt['q'])
				(void) printf("failed to read label %d\n", l);
			label->read_failed = B_TRUE;
			error = B_TRUE;
			continue;
		}

		label->read_failed = B_FALSE;
		label->cksum_valid = label_cksum_valid(&label->label,
		    label->label_offset);

		if (nvlist_unpack(buf, buflen, &config, 0) == 0) {
			nvlist_t *vdev_tree = NULL;
			size_t size;

			if ((nvlist_lookup_nvlist(config,
			    ZPOOL_CONFIG_VDEV_TREE, &vdev_tree) != 0) ||
			    (nvlist_lookup_uint64(vdev_tree,
			    ZPOOL_CONFIG_ASHIFT, &ashift) != 0))
				ashift = SPA_MINBLOCKSHIFT;

			if (nvlist_size(config, &size, NV_ENCODE_XDR) != 0)
				size = buflen;

			/* If the device is a cache device read the header. */
			if (!read_l2arc_header) {
				if (nvlist_lookup_uint64(config,
				    ZPOOL_CONFIG_POOL_STATE, &l2cache) == 0 &&
				    l2cache == POOL_STATE_L2CACHE) {
					read_l2arc_header = B_TRUE;
				}
			}

			fletcher_4_native_varsize(buf, size, &cksum);
			rec = cksum_record_insert(&config_tree, &cksum, l);

			label->config = rec;
			label->config_nv = config;
			config_found = B_TRUE;
		} else {
			error = B_TRUE;
		}

		vd.vdev_ashift = ashift;
		vd.vdev_top = &vd;

		for (int i = 0; i < VDEV_UBERBLOCK_COUNT(&vd); i++) {
			uint64_t uoff = VDEV_UBERBLOCK_OFFSET(&vd, i);
			uberblock_t *ub = (void *)((char *)label + uoff);

			if (uberblock_verify(ub))
				continue;

			fletcher_4_native_varsize(ub, sizeof (*ub), &cksum);
			rec = cksum_record_insert(&uberblock_tree, &cksum, l);

			label->uberblocks[i] = rec;
		}
	}

	/*
	 * Dump the label and uberblocks.
	 */
	for (int l = 0; l < VDEV_LABELS; l++) {
		zdb_label_t *label = &labels[l];
		size_t buflen = sizeof (label->label.vl_vdev_phys.vp_nvlist);

		if (label->read_failed == B_TRUE)
			continue;

		if (label->config_nv) {
			dump_config_from_label(label, buflen, l);
		} else {
			if (!dump_opt['q'])
				(void) printf("failed to unpack label %d\n", l);
		}

		if (dump_opt['u'])
			dump_label_uberblocks(label, ashift, l);

		nvlist_free(label->config_nv);
	}

	/*
	 * Dump the L2ARC header, if existent.
	 */
	if (read_l2arc_header)
		error |= dump_l2arc_header(fd);

	cookie = NULL;
	while ((node = avl_destroy_nodes(&config_tree, &cookie)) != NULL)
		umem_free(node, sizeof (cksum_record_t));

	cookie = NULL;
	while ((node = avl_destroy_nodes(&uberblock_tree, &cookie)) != NULL)
		umem_free(node, sizeof (cksum_record_t));

	avl_destroy(&config_tree);
	avl_destroy(&uberblock_tree);

	(void) close(fd);

	return (config_found == B_FALSE ? 2 :
	    (error == B_TRUE ? 1 : 0));
}

static uint64_t dataset_feature_count[SPA_FEATURES];
static uint64_t global_feature_count[SPA_FEATURES];
static uint64_t remap_deadlist_count = 0;

static int
dump_one_objset(const char *dsname, void *arg)
{
	(void) arg;
	int error;
	objset_t *os;
	spa_feature_t f;

	error = open_objset(dsname, FTAG, &os);
	if (error != 0)
		return (0);

	for (f = 0; f < SPA_FEATURES; f++) {
		if (!dsl_dataset_feature_is_active(dmu_objset_ds(os), f))
			continue;
		ASSERT(spa_feature_table[f].fi_flags &
		    ZFEATURE_FLAG_PER_DATASET);
		dataset_feature_count[f]++;
	}

	if (dsl_dataset_remap_deadlist_exists(dmu_objset_ds(os))) {
		remap_deadlist_count++;
	}

	for (dsl_bookmark_node_t *dbn =
	    avl_first(&dmu_objset_ds(os)->ds_bookmarks); dbn != NULL;
	    dbn = AVL_NEXT(&dmu_objset_ds(os)->ds_bookmarks, dbn)) {
		mos_obj_refd(dbn->dbn_phys.zbm_redaction_obj);
		if (dbn->dbn_phys.zbm_redaction_obj != 0) {
			global_feature_count[
			    SPA_FEATURE_REDACTION_BOOKMARKS]++;
			objset_t *mos = os->os_spa->spa_meta_objset;
			dnode_t *rl;
			VERIFY0(dnode_hold(mos,
			    dbn->dbn_phys.zbm_redaction_obj, FTAG, &rl));
			if (rl->dn_have_spill) {
				global_feature_count[
				    SPA_FEATURE_REDACTION_LIST_SPILL]++;
			}
		}
		if (dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN)
			global_feature_count[SPA_FEATURE_BOOKMARK_WRITTEN]++;
	}

	if (dsl_deadlist_is_open(&dmu_objset_ds(os)->ds_dir->dd_livelist) &&
	    !dmu_objset_is_snapshot(os)) {
		global_feature_count[SPA_FEATURE_LIVELIST]++;
	}

	dump_objset(os);
	close_objset(os, FTAG);
	fuid_table_destroy();
	return (0);
}

/*
 * Block statistics.
 */
#define	PSIZE_HISTO_SIZE (SPA_OLD_MAXBLOCKSIZE / SPA_MINBLOCKSIZE + 2)
typedef struct zdb_blkstats {
	uint64_t zb_asize;
	uint64_t zb_lsize;
	uint64_t zb_psize;
	uint64_t zb_count;
	uint64_t zb_gangs;
	uint64_t zb_ditto_samevdev;
	uint64_t zb_ditto_same_ms;
	uint64_t zb_psize_histogram[PSIZE_HISTO_SIZE];
} zdb_blkstats_t;

/*
 * Extended object types to report deferred frees and dedup auto-ditto blocks.
 */
#define	ZDB_OT_DEFERRED	(DMU_OT_NUMTYPES + 0)
#define	ZDB_OT_DITTO	(DMU_OT_NUMTYPES + 1)
#define	ZDB_OT_OTHER	(DMU_OT_NUMTYPES + 2)
#define	ZDB_OT_TOTAL	(DMU_OT_NUMTYPES + 3)

static const char *zdb_ot_extname[] = {
	"deferred free",
	"dedup ditto",
	"other",
	"Total",
};

#define	ZB_TOTAL	DN_MAX_LEVELS
#define	SPA_MAX_FOR_16M	(SPA_MAXBLOCKSHIFT+1)

typedef struct zdb_brt_entry {
	dva_t		zbre_dva;
	uint64_t	zbre_refcount;
	avl_node_t	zbre_node;
} zdb_brt_entry_t;

typedef struct zdb_cb {
	zdb_blkstats_t	zcb_type[ZB_TOTAL + 1][ZDB_OT_TOTAL + 1];
	uint64_t	zcb_removing_size;
	uint64_t	zcb_checkpoint_size;
	uint64_t	zcb_dedup_asize;
	uint64_t	zcb_dedup_blocks;
	uint64_t	zcb_clone_asize;
	uint64_t	zcb_clone_blocks;
	uint64_t	zcb_psize_count[SPA_MAX_FOR_16M];
	uint64_t	zcb_lsize_count[SPA_MAX_FOR_16M];
	uint64_t	zcb_asize_count[SPA_MAX_FOR_16M];
	uint64_t	zcb_psize_len[SPA_MAX_FOR_16M];
	uint64_t	zcb_lsize_len[SPA_MAX_FOR_16M];
	uint64_t	zcb_asize_len[SPA_MAX_FOR_16M];
	uint64_t	zcb_psize_total;
	uint64_t	zcb_lsize_total;
	uint64_t	zcb_asize_total;
	uint64_t	zcb_embedded_blocks[NUM_BP_EMBEDDED_TYPES];
	uint64_t	zcb_embedded_histogram[NUM_BP_EMBEDDED_TYPES]
	    [BPE_PAYLOAD_SIZE + 1];
	uint64_t	zcb_start;
	hrtime_t	zcb_lastprint;
	uint64_t	zcb_totalasize;
	uint64_t	zcb_errors[256];
	int		zcb_readfails;
	int		zcb_haderrors;
	spa_t		*zcb_spa;
	uint32_t	**zcb_vd_obsolete_counts;
	avl_tree_t	zcb_brt;
	boolean_t	zcb_brt_is_active;
} zdb_cb_t;

/* test if two DVA offsets from same vdev are within the same metaslab */
static boolean_t
same_metaslab(spa_t *spa, uint64_t vdev, uint64_t off1, uint64_t off2)
{
	vdev_t *vd = vdev_lookup_top(spa, vdev);
	uint64_t ms_shift = vd->vdev_ms_shift;

	return ((off1 >> ms_shift) == (off2 >> ms_shift));
}

/*
 * Used to simplify reporting of the histogram data.
 */
typedef struct one_histo {
	const char *name;
	uint64_t *count;
	uint64_t *len;
	uint64_t cumulative;
} one_histo_t;

/*
 * The number of separate histograms processed for psize, lsize and asize.
 */
#define	NUM_HISTO 3

/*
 * This routine will create a fixed column size output of three different
 * histograms showing by blocksize of 512 - 2^ SPA_MAX_FOR_16M
 * the count, length and cumulative length of the psize, lsize and
 * asize blocks.
 *
 * All three types of blocks are listed on a single line
 *
 * By default the table is printed in nicenumber format (e.g. 123K) but
 * if the '-P' parameter is specified then the full raw number (parseable)
 * is printed out.
 */
static void
dump_size_histograms(zdb_cb_t *zcb)
{
	/*
	 * A temporary buffer that allows us to convert a number into
	 * a string using zdb_nicenumber to allow either raw or human
	 * readable numbers to be output.
	 */
	char numbuf[32];

	/*
	 * Define titles which are used in the headers of the tables
	 * printed by this routine.
	 */
	const char blocksize_title1[] = "block";
	const char blocksize_title2[] = "size";
	const char count_title[] = "Count";
	const char length_title[] = "Size";
	const char cumulative_title[] = "Cum.";

	/*
	 * Setup the histogram arrays (psize, lsize, and asize).
	 */
	one_histo_t parm_histo[NUM_HISTO];

	parm_histo[0].name = "psize";
	parm_histo[0].count = zcb->zcb_psize_count;
	parm_histo[0].len = zcb->zcb_psize_len;
	parm_histo[0].cumulative = 0;

	parm_histo[1].name = "lsize";
	parm_histo[1].count = zcb->zcb_lsize_count;
	parm_histo[1].len = zcb->zcb_lsize_len;
	parm_histo[1].cumulative = 0;

	parm_histo[2].name = "asize";
	parm_histo[2].count = zcb->zcb_asize_count;
	parm_histo[2].len = zcb->zcb_asize_len;
	parm_histo[2].cumulative = 0;


	(void) printf("\nBlock Size Histogram\n");
	/*
	 * Print the first line titles
	 */
	if (dump_opt['P'])
		(void) printf("\n%s\t", blocksize_title1);
	else
		(void) printf("\n%7s   ", blocksize_title1);

	for (int j = 0; j < NUM_HISTO; j++) {
		if (dump_opt['P']) {
			if (j < NUM_HISTO - 1) {
				(void) printf("%s\t\t\t", parm_histo[j].name);
			} else {
				/* Don't print trailing spaces */
				(void) printf("  %s", parm_histo[j].name);
			}
		} else {
			if (j < NUM_HISTO - 1) {
				/* Left aligned strings in the output */
				(void) printf("%-7s              ",
				    parm_histo[j].name);
			} else {
				/* Don't print trailing spaces */
				(void) printf("%s", parm_histo[j].name);
			}
		}
	}
	(void) printf("\n");

	/*
	 * Print the second line titles
	 */
	if (dump_opt['P']) {
		(void) printf("%s\t", blocksize_title2);
	} else {
		(void) printf("%7s ", blocksize_title2);
	}

	for (int i = 0; i < NUM_HISTO; i++) {
		if (dump_opt['P']) {
			(void) printf("%s\t%s\t%s\t",
			    count_title, length_title, cumulative_title);
		} else {
			(void) printf("%7s%7s%7s",
			    count_title, length_title, cumulative_title);
		}
	}
	(void) printf("\n");

	/*
	 * Print the rows
	 */
	for (int i = SPA_MINBLOCKSHIFT; i < SPA_MAX_FOR_16M; i++) {

		/*
		 * Print the first column showing the blocksize
		 */
		zdb_nicenum((1ULL << i), numbuf, sizeof (numbuf));

		if (dump_opt['P']) {
			printf("%s", numbuf);
		} else {
			printf("%7s:", numbuf);
		}

		/*
		 * Print the remaining set of 3 columns per size:
		 * for psize, lsize and asize
		 */
		for (int j = 0; j < NUM_HISTO; j++) {
			parm_histo[j].cumulative += parm_histo[j].len[i];

			zdb_nicenum(parm_histo[j].count[i],
			    numbuf, sizeof (numbuf));
			if (dump_opt['P'])
				(void) printf("\t%s", numbuf);
			else
				(void) printf("%7s", numbuf);

			zdb_nicenum(parm_histo[j].len[i],
			    numbuf, sizeof (numbuf));
			if (dump_opt['P'])
				(void) printf("\t%s", numbuf);
			else
				(void) printf("%7s", numbuf);

			zdb_nicenum(parm_histo[j].cumulative,
			    numbuf, sizeof (numbuf));
			if (dump_opt['P'])
				(void) printf("\t%s", numbuf);
			else
				(void) printf("%7s", numbuf);
		}
		(void) printf("\n");
	}
}

static void
zdb_count_block(zdb_cb_t *zcb, zilog_t *zilog, const blkptr_t *bp,
    dmu_object_type_t type)
{
	int i;

	ASSERT(type < ZDB_OT_TOTAL);

	if (zilog && zil_bp_tree_add(zilog, bp) != 0)
		return;

	/*
	 * This flag controls if we will issue a claim for the block while
	 * counting it, to ensure that all blocks are referenced in space maps.
	 * We don't issue claims if we're not doing leak tracking, because it's
	 * expensive if the user isn't interested. We also don't claim the
	 * second or later occurences of cloned or dedup'd blocks, because we
	 * already claimed them the first time.
	 */
	boolean_t do_claim = !dump_opt['L'];

	spa_config_enter(zcb->zcb_spa, SCL_CONFIG, FTAG, RW_READER);

	blkptr_t tempbp;
	if (BP_GET_DEDUP(bp)) {
		/*
		 * Dedup'd blocks are special. We need to count them, so we can
		 * later uncount them when reporting leaked space, and we must
		 * only claim them once.
		 *
		 * We use the existing dedup system to track what we've seen.
		 * The first time we see a block, we do a ddt_lookup() to see
		 * if it exists in the DDT. If we're doing leak tracking, we
		 * claim the block at this time.
		 *
		 * Each time we see a block, we reduce the refcount in the
		 * entry by one, and add to the size and count of dedup'd
		 * blocks to report at the end.
		 */

		ddt_t *ddt = ddt_select(zcb->zcb_spa, bp);

		ddt_enter(ddt);

		/*
		 * Find the block. This will create the entry in memory, but
		 * we'll know if that happened by its refcount.
		 */
		ddt_entry_t *dde = ddt_lookup(ddt, bp, B_TRUE);

		/*
		 * ddt_lookup() can return NULL if this block didn't exist
		 * in the DDT and creating it would take the DDT over its
		 * quota. Since we got the block from disk, it must exist in
		 * the DDT, so this can't happen. However, when unique entries
		 * are pruned, the dedup bit can be set with no corresponding
		 * entry in the DDT.
		 */
		if (dde == NULL) {
			ddt_exit(ddt);
			goto skipped;
		}

		/* Get the phys for this variant */
		ddt_phys_variant_t v = ddt_phys_select(ddt, dde, bp);

		/*
		 * This entry may have multiple sets of DVAs. We must claim
		 * each set the first time we see them in a real block on disk,
		 * or count them on subsequent occurences. We don't have a
		 * convenient way to track the first time we see each variant,
		 * so we repurpose dde_io as a set of "seen" flag bits. We can
		 * do this safely in zdb because it never writes, so it will
		 * never have a writing zio for this block in that pointer.
		 */
		boolean_t seen = !!(((uintptr_t)dde->dde_io) & (1 << v));
		if (!seen)
			dde->dde_io =
			    (void *)(((uintptr_t)dde->dde_io) | (1 << v));

		/* Consume a reference for this block. */
		if (ddt_phys_total_refcnt(ddt, dde->dde_phys) > 0)
			ddt_phys_decref(dde->dde_phys, v);

		/*
		 * If this entry has a single flat phys, it may have been
		 * extended with additional DVAs at some time in its life.
		 * This block might be from before it was fully extended, and
		 * so have fewer DVAs.
		 *
		 * If this is the first time we've seen this block, and we
		 * claimed it as-is, then we would miss the claim on some
		 * number of DVAs, which would then be seen as leaked.
		 *
		 * In all cases, if we've had fewer DVAs, then the asize would
		 * be too small, and would lead to the pool apparently using
		 * more space than allocated.
		 *
		 * To handle this, we copy the canonical set of DVAs from the
		 * entry back to the block pointer before we claim it.
		 */
		if (v == DDT_PHYS_FLAT) {
			ASSERT3U(BP_GET_PHYSICAL_BIRTH(bp), ==,
			    ddt_phys_birth(dde->dde_phys, v));
			tempbp = *bp;
			ddt_bp_fill(dde->dde_phys, v, &tempbp,
			    BP_GET_PHYSICAL_BIRTH(bp));
			bp = &tempbp;
		}

		if (seen) {
			/*
			 * The second or later time we see this block,
			 * it's a duplicate and we count it.
			 */
			zcb->zcb_dedup_asize += BP_GET_ASIZE(bp);
			zcb->zcb_dedup_blocks++;

			/* Already claimed, don't do it again. */
			do_claim = B_FALSE;
		}

		ddt_exit(ddt);
	} else if (zcb->zcb_brt_is_active &&
	    brt_maybe_exists(zcb->zcb_spa, bp)) {
		/*
		 * Cloned blocks are special. We need to count them, so we can
		 * later uncount them when reporting leaked space, and we must
		 * only claim them once.
		 *
		 * To do this, we keep our own in-memory BRT. For each block
		 * we haven't seen before, we look it up in the real BRT and
		 * if its there, we note it and its refcount then proceed as
		 * normal. If we see the block again, we count it as a clone
		 * and then give it no further consideration.
		 */
		zdb_brt_entry_t zbre_search, *zbre;
		avl_index_t where;

		zbre_search.zbre_dva = bp->blk_dva[0];
		zbre = avl_find(&zcb->zcb_brt, &zbre_search, &where);
		if (zbre == NULL) {
			/* Not seen before; track it */
			uint64_t refcnt =
			    brt_entry_get_refcount(zcb->zcb_spa, bp);
			if (refcnt > 0) {
				zbre = umem_zalloc(sizeof (zdb_brt_entry_t),
				    UMEM_NOFAIL);
				zbre->zbre_dva = bp->blk_dva[0];
				zbre->zbre_refcount = refcnt;
				avl_insert(&zcb->zcb_brt, zbre, where);
			}
		} else  {
			/*
			 * Second or later occurrence, count it and take a
			 * refcount.
			 */
			zcb->zcb_clone_asize += BP_GET_ASIZE(bp);
			zcb->zcb_clone_blocks++;

			zbre->zbre_refcount--;
			if (zbre->zbre_refcount == 0) {
				avl_remove(&zcb->zcb_brt, zbre);
				umem_free(zbre, sizeof (zdb_brt_entry_t));
			}

			/* Already claimed, don't do it again. */
			do_claim = B_FALSE;
		}
	}

skipped:
	for (i = 0; i < 4; i++) {
		int l = (i < 2) ? BP_GET_LEVEL(bp) : ZB_TOTAL;
		int t = (i & 1) ? type : ZDB_OT_TOTAL;
		int equal;
		zdb_blkstats_t *zb = &zcb->zcb_type[l][t];

		zb->zb_asize += BP_GET_ASIZE(bp);
		zb->zb_lsize += BP_GET_LSIZE(bp);
		zb->zb_psize += BP_GET_PSIZE(bp);
		zb->zb_count++;

		/*
		 * The histogram is only big enough to record blocks up to
		 * SPA_OLD_MAXBLOCKSIZE; larger blocks go into the last,
		 * "other", bucket.
		 */
		unsigned idx = BP_GET_PSIZE(bp) >> SPA_MINBLOCKSHIFT;
		idx = MIN(idx, SPA_OLD_MAXBLOCKSIZE / SPA_MINBLOCKSIZE + 1);
		zb->zb_psize_histogram[idx]++;

		zb->zb_gangs += BP_COUNT_GANG(bp);

		switch (BP_GET_NDVAS(bp)) {
		case 2:
			if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
			    DVA_GET_VDEV(&bp->blk_dva[1])) {
				zb->zb_ditto_samevdev++;

				if (same_metaslab(zcb->zcb_spa,
				    DVA_GET_VDEV(&bp->blk_dva[0]),
				    DVA_GET_OFFSET(&bp->blk_dva[0]),
				    DVA_GET_OFFSET(&bp->blk_dva[1])))
					zb->zb_ditto_same_ms++;
			}
			break;
		case 3:
			equal = (DVA_GET_VDEV(&bp->blk_dva[0]) ==
			    DVA_GET_VDEV(&bp->blk_dva[1])) +
			    (DVA_GET_VDEV(&bp->blk_dva[0]) ==
			    DVA_GET_VDEV(&bp->blk_dva[2])) +
			    (DVA_GET_VDEV(&bp->blk_dva[1]) ==
			    DVA_GET_VDEV(&bp->blk_dva[2]));
			if (equal != 0) {
				zb->zb_ditto_samevdev++;

				if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
				    DVA_GET_VDEV(&bp->blk_dva[1]) &&
				    same_metaslab(zcb->zcb_spa,
				    DVA_GET_VDEV(&bp->blk_dva[0]),
				    DVA_GET_OFFSET(&bp->blk_dva[0]),
				    DVA_GET_OFFSET(&bp->blk_dva[1])))
					zb->zb_ditto_same_ms++;
				else if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
				    DVA_GET_VDEV(&bp->blk_dva[2]) &&
				    same_metaslab(zcb->zcb_spa,
				    DVA_GET_VDEV(&bp->blk_dva[0]),
				    DVA_GET_OFFSET(&bp->blk_dva[0]),
				    DVA_GET_OFFSET(&bp->blk_dva[2])))
					zb->zb_ditto_same_ms++;
				else if (DVA_GET_VDEV(&bp->blk_dva[1]) ==
				    DVA_GET_VDEV(&bp->blk_dva[2]) &&
				    same_metaslab(zcb->zcb_spa,
				    DVA_GET_VDEV(&bp->blk_dva[1]),
				    DVA_GET_OFFSET(&bp->blk_dva[1]),
				    DVA_GET_OFFSET(&bp->blk_dva[2])))
					zb->zb_ditto_same_ms++;
			}
			break;
		}
	}

	spa_config_exit(zcb->zcb_spa, SCL_CONFIG, FTAG);

	if (BP_IS_EMBEDDED(bp)) {
		zcb->zcb_embedded_blocks[BPE_GET_ETYPE(bp)]++;
		zcb->zcb_embedded_histogram[BPE_GET_ETYPE(bp)]
		    [BPE_GET_PSIZE(bp)]++;
		return;
	}
	/*
	 * The binning histogram bins by powers of two up to
	 * SPA_MAXBLOCKSIZE rather than creating bins for
	 * every possible blocksize found in the pool.
	 */
	int bin = highbit64(BP_GET_PSIZE(bp)) - 1;

	zcb->zcb_psize_count[bin]++;
	zcb->zcb_psize_len[bin] += BP_GET_PSIZE(bp);
	zcb->zcb_psize_total += BP_GET_PSIZE(bp);

	bin = highbit64(BP_GET_LSIZE(bp)) - 1;

	zcb->zcb_lsize_count[bin]++;
	zcb->zcb_lsize_len[bin] += BP_GET_LSIZE(bp);
	zcb->zcb_lsize_total += BP_GET_LSIZE(bp);

	bin = highbit64(BP_GET_ASIZE(bp)) - 1;

	zcb->zcb_asize_count[bin]++;
	zcb->zcb_asize_len[bin] += BP_GET_ASIZE(bp);
	zcb->zcb_asize_total += BP_GET_ASIZE(bp);

	if (!do_claim)
		return;

	VERIFY0(zio_wait(zio_claim(NULL, zcb->zcb_spa,
	    spa_min_claim_txg(zcb->zcb_spa), bp, NULL, NULL,
	    ZIO_FLAG_CANFAIL)));
}

static void
zdb_blkptr_done(zio_t *zio)
{
	spa_t *spa = zio->io_spa;
	blkptr_t *bp = zio->io_bp;
	int ioerr = zio->io_error;
	zdb_cb_t *zcb = zio->io_private;
	zbookmark_phys_t *zb = &zio->io_bookmark;

	mutex_enter(&spa->spa_scrub_lock);
	spa->spa_load_verify_bytes -= BP_GET_PSIZE(bp);
	cv_broadcast(&spa->spa_scrub_io_cv);

	if (ioerr && !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
		char blkbuf[BP_SPRINTF_LEN];

		zcb->zcb_haderrors = 1;
		zcb->zcb_errors[ioerr]++;

		if (dump_opt['b'] >= 2)
			snprintf_blkptr(blkbuf, sizeof (blkbuf), bp);
		else
			blkbuf[0] = '\0';

		(void) printf("zdb_blkptr_cb: "
		    "Got error %d reading "
		    "<%llu, %llu, %lld, %llx> %s -- skipping\n",
		    ioerr,
		    (u_longlong_t)zb->zb_objset,
		    (u_longlong_t)zb->zb_object,
		    (u_longlong_t)zb->zb_level,
		    (u_longlong_t)zb->zb_blkid,
		    blkbuf);
	}
	mutex_exit(&spa->spa_scrub_lock);

	abd_free(zio->io_abd);
}

static int
zdb_blkptr_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
    const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
{
	zdb_cb_t *zcb = arg;
	dmu_object_type_t type;
	boolean_t is_metadata;

	if (zb->zb_level == ZB_DNODE_LEVEL)
		return (0);

	if (dump_opt['b'] >= 5 && BP_GET_BIRTH(bp) > 0) {
		char blkbuf[BP_SPRINTF_LEN];
		snprintf_blkptr(blkbuf, sizeof (blkbuf), bp);
		(void) printf("objset %llu object %llu "
		    "level %lld offset 0x%llx %s\n",
		    (u_longlong_t)zb->zb_objset,
		    (u_longlong_t)zb->zb_object,
		    (longlong_t)zb->zb_level,
		    (u_longlong_t)blkid2offset(dnp, bp, zb),
		    blkbuf);
	}

	if (BP_IS_HOLE(bp) || BP_IS_REDACTED(bp))
		return (0);

	type = BP_GET_TYPE(bp);

	zdb_count_block(zcb, zilog, bp,
	    (type & DMU_OT_NEWTYPE) ? ZDB_OT_OTHER : type);

	is_metadata = (BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type));

	if (!BP_IS_EMBEDDED(bp) &&
	    (dump_opt['c'] > 1 || (dump_opt['c'] && is_metadata))) {
		size_t size = BP_GET_PSIZE(bp);
		abd_t *abd = abd_alloc(size, B_FALSE);
		int flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCRUB | ZIO_FLAG_RAW;

		/* If it's an intent log block, failure is expected. */
		if (zb->zb_level == ZB_ZIL_LEVEL)
			flags |= ZIO_FLAG_SPECULATIVE;

		mutex_enter(&spa->spa_scrub_lock);
		while (spa->spa_load_verify_bytes > max_inflight_bytes)
			cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
		spa->spa_load_verify_bytes += size;
		mutex_exit(&spa->spa_scrub_lock);

		zio_nowait(zio_read(NULL, spa, bp, abd, size,
		    zdb_blkptr_done, zcb, ZIO_PRIORITY_ASYNC_READ, flags, zb));
	}

	zcb->zcb_readfails = 0;

	/* only call gethrtime() every 100 blocks */
	static int iters;
	if (++iters > 100)
		iters = 0;
	else
		return (0);

	if (dump_opt['b'] < 5 && gethrtime() > zcb->zcb_lastprint + NANOSEC) {
		uint64_t now = gethrtime();
		char buf[10];
		uint64_t bytes = zcb->zcb_type[ZB_TOTAL][ZDB_OT_TOTAL].zb_asize;
		uint64_t kb_per_sec =
		    1 + bytes / (1 + ((now - zcb->zcb_start) / 1000 / 1000));
		uint64_t sec_remaining =
		    (zcb->zcb_totalasize - bytes) / 1024 / kb_per_sec;

		/* make sure nicenum has enough space */
		_Static_assert(sizeof (buf) >= NN_NUMBUF_SZ, "buf truncated");

		zfs_nicebytes(bytes, buf, sizeof (buf));
		(void) fprintf(stderr,
		    "\r%5s completed (%4"PRIu64"MB/s) "
		    "estimated time remaining: "
		    "%"PRIu64"hr %02"PRIu64"min %02"PRIu64"sec        ",
		    buf, kb_per_sec / 1024,
		    sec_remaining / 60 / 60,
		    sec_remaining / 60 % 60,
		    sec_remaining % 60);

		zcb->zcb_lastprint = now;
	}

	return (0);
}

static void
zdb_leak(void *arg, uint64_t start, uint64_t size)
{
	vdev_t *vd = arg;

	(void) printf("leaked space: vdev %llu, offset 0x%llx, size %llu\n",
	    (u_longlong_t)vd->vdev_id, (u_longlong_t)start, (u_longlong_t)size);
}

static metaslab_ops_t zdb_metaslab_ops = {
	NULL	/* alloc */
};

static int
load_unflushed_svr_segs_cb(spa_t *spa, space_map_entry_t *sme,
    uint64_t txg, void *arg)
{
	spa_vdev_removal_t *svr = arg;

	uint64_t offset = sme->sme_offset;
	uint64_t size = sme->sme_run;

	/* skip vdevs we don't care about */
	if (sme->sme_vdev != svr->svr_vdev_id)
		return (0);

	vdev_t *vd = vdev_lookup_top(spa, sme->sme_vdev);
	metaslab_t *ms = vd->vdev_ms[offset >> vd->vdev_ms_shift];
	ASSERT(sme->sme_type == SM_ALLOC || sme->sme_type == SM_FREE);

	if (txg < metaslab_unflushed_txg(ms))
		return (0);

	if (sme->sme_type == SM_ALLOC)
		zfs_range_tree_add(svr->svr_allocd_segs, offset, size);
	else
		zfs_range_tree_remove(svr->svr_allocd_segs, offset, size);

	return (0);
}

static void
claim_segment_impl_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset,
    uint64_t size, void *arg)
{
	(void) inner_offset, (void) arg;

	/*
	 * This callback was called through a remap from
	 * a device being removed. Therefore, the vdev that
	 * this callback is applied to is a concrete
	 * vdev.
	 */
	ASSERT(vdev_is_concrete(vd));

	VERIFY0(metaslab_claim_impl(vd, offset, size,
	    spa_min_claim_txg(vd->vdev_spa)));
}

static void
claim_segment_cb(void *arg, uint64_t offset, uint64_t size)
{
	vdev_t *vd = arg;

	vdev_indirect_ops.vdev_op_remap(vd, offset, size,
	    claim_segment_impl_cb, NULL);
}

/*
 * After accounting for all allocated blocks that are directly referenced,
 * we might have missed a reference to a block from a partially complete
 * (and thus unused) indirect mapping object. We perform a secondary pass
 * through the metaslabs we have already mapped and claim the destination
 * blocks.
 */
static void
zdb_claim_removing(spa_t *spa, zdb_cb_t *zcb)
{
	if (dump_opt['L'])
		return;

	if (spa->spa_vdev_removal == NULL)
		return;

	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);

	spa_vdev_removal_t *svr = spa->spa_vdev_removal;
	vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id);
	vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;

	ASSERT0(zfs_range_tree_space(svr->svr_allocd_segs));

	zfs_range_tree_t *allocs = zfs_range_tree_create_flags(
	    NULL, ZFS_RANGE_SEG64, NULL, 0, 0,
	    0, "zdb_claim_removing:allocs");
	for (uint64_t msi = 0; msi < vd->vdev_ms_count; msi++) {
		metaslab_t *msp = vd->vdev_ms[msi];

		ASSERT0(zfs_range_tree_space(allocs));
		if (msp->ms_sm != NULL)
			VERIFY0(space_map_load(msp->ms_sm, allocs, SM_ALLOC));
		zfs_range_tree_vacate(allocs, zfs_range_tree_add,
		    svr->svr_allocd_segs);
	}
	zfs_range_tree_destroy(allocs);

	iterate_through_spacemap_logs(spa, load_unflushed_svr_segs_cb, svr);

	/*
	 * Clear everything past what has been synced,
	 * because we have not allocated mappings for
	 * it yet.
	 */
	zfs_range_tree_clear(svr->svr_allocd_segs,
	    vdev_indirect_mapping_max_offset(vim),
	    vd->vdev_asize - vdev_indirect_mapping_max_offset(vim));

	zcb->zcb_removing_size += zfs_range_tree_space(svr->svr_allocd_segs);
	zfs_range_tree_vacate(svr->svr_allocd_segs, claim_segment_cb, vd);

	spa_config_exit(spa, SCL_CONFIG, FTAG);
}

static int
increment_indirect_mapping_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
    dmu_tx_t *tx)
{
	(void) tx;
	zdb_cb_t *zcb = arg;
	spa_t *spa = zcb->zcb_spa;
	vdev_t *vd;
	const dva_t *dva = &bp->blk_dva[0];

	ASSERT(!bp_freed);
	ASSERT(!dump_opt['L']);
	ASSERT3U(BP_GET_NDVAS(bp), ==, 1);

	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
	vd = vdev_lookup_top(zcb->zcb_spa, DVA_GET_VDEV(dva));
	ASSERT3P(vd, !=, NULL);
	spa_config_exit(spa, SCL_VDEV, FTAG);

	ASSERT(vd->vdev_indirect_config.vic_mapping_object != 0);
	ASSERT3P(zcb->zcb_vd_obsolete_counts[vd->vdev_id], !=, NULL);

	vdev_indirect_mapping_increment_obsolete_count(
	    vd->vdev_indirect_mapping,
	    DVA_GET_OFFSET(dva), DVA_GET_ASIZE(dva),
	    zcb->zcb_vd_obsolete_counts[vd->vdev_id]);

	return (0);
}

static uint32_t *
zdb_load_obsolete_counts(vdev_t *vd)
{
	vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;
	spa_t *spa = vd->vdev_spa;
	spa_condensing_indirect_phys_t *scip =
	    &spa->spa_condensing_indirect_phys;
	uint64_t obsolete_sm_object;
	uint32_t *counts;

	VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
	EQUIV(obsolete_sm_object != 0, vd->vdev_obsolete_sm != NULL);
	counts = vdev_indirect_mapping_load_obsolete_counts(vim);
	if (vd->vdev_obsolete_sm != NULL) {
		vdev_indirect_mapping_load_obsolete_spacemap(vim, counts,
		    vd->vdev_obsolete_sm);
	}
	if (scip->scip_vdev == vd->vdev_id &&
	    scip->scip_prev_obsolete_sm_object != 0) {
		space_map_t *prev_obsolete_sm = NULL;
		VERIFY0(space_map_open(&prev_obsolete_sm, spa->spa_meta_objset,
		    scip->scip_prev_obsolete_sm_object, 0, vd->vdev_asize, 0));
		vdev_indirect_mapping_load_obsolete_spacemap(vim, counts,
		    prev_obsolete_sm);
		space_map_close(prev_obsolete_sm);
	}
	return (counts);
}

typedef struct checkpoint_sm_exclude_entry_arg {
	vdev_t *cseea_vd;
	uint64_t cseea_checkpoint_size;
} checkpoint_sm_exclude_entry_arg_t;

static int
checkpoint_sm_exclude_entry_cb(space_map_entry_t *sme, void *arg)
{
	checkpoint_sm_exclude_entry_arg_t *cseea = arg;
	vdev_t *vd = cseea->cseea_vd;
	metaslab_t *ms = vd->vdev_ms[sme->sme_offset >> vd->vdev_ms_shift];
	uint64_t end = sme->sme_offset + sme->sme_run;

	ASSERT(sme->sme_type == SM_FREE);

	/*
	 * Since the vdev_checkpoint_sm exists in the vdev level
	 * and the ms_sm space maps exist in the metaslab level,
	 * an entry in the checkpoint space map could theoretically
	 * cross the boundaries of the metaslab that it belongs.
	 *
	 * In reality, because of the way that we populate and
	 * manipulate the checkpoint's space maps currently,
	 * there shouldn't be any entries that cross metaslabs.
	 * Hence the assertion below.
	 *
	 * That said, there is no fundamental requirement that
	 * the checkpoint's space map entries should not cross
	 * metaslab boundaries. So if needed we could add code
	 * that handles metaslab-crossing segments in the future.
	 */
	VERIFY3U(sme->sme_offset, >=, ms->ms_start);
	VERIFY3U(end, <=, ms->ms_start + ms->ms_size);

	/*
	 * By removing the entry from the allocated segments we
	 * also verify that the entry is there to begin with.
	 */
	mutex_enter(&ms->ms_lock);
	zfs_range_tree_remove(ms->ms_allocatable, sme->sme_offset,
	    sme->sme_run);
	mutex_exit(&ms->ms_lock);

	cseea->cseea_checkpoint_size += sme->sme_run;
	return (0);
}

static void
zdb_leak_init_vdev_exclude_checkpoint(vdev_t *vd, zdb_cb_t *zcb)
{
	spa_t *spa = vd->vdev_spa;
	space_map_t *checkpoint_sm = NULL;
	uint64_t checkpoint_sm_obj;

	/*
	 * If there is no vdev_top_zap, we are in a pool whose
	 * version predates the pool checkpoint feature.
	 */
	if (vd->vdev_top_zap == 0)
		return;

	/*
	 * If there is no reference of the vdev_checkpoint_sm in
	 * the vdev_top_zap, then one of the following scenarios
	 * is true:
	 *
	 * 1] There is no checkpoint
	 * 2] There is a checkpoint, but no checkpointed blocks
	 *    have been freed yet
	 * 3] The current vdev is indirect
	 *
	 * In these cases we return immediately.
	 */
	if (zap_contains(spa_meta_objset(spa), vd->vdev_top_zap,
	    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM) != 0)
		return;

	VERIFY0(zap_lookup(spa_meta_objset(spa), vd->vdev_top_zap,
	    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM, sizeof (uint64_t), 1,
	    &checkpoint_sm_obj));

	checkpoint_sm_exclude_entry_arg_t cseea;
	cseea.cseea_vd = vd;
	cseea.cseea_checkpoint_size = 0;

	VERIFY0(space_map_open(&checkpoint_sm, spa_meta_objset(spa),
	    checkpoint_sm_obj, 0, vd->vdev_asize, vd->vdev_ashift));

	VERIFY0(space_map_iterate(checkpoint_sm,
	    space_map_length(checkpoint_sm),
	    checkpoint_sm_exclude_entry_cb, &cseea));
	space_map_close(checkpoint_sm);

	zcb->zcb_checkpoint_size += cseea.cseea_checkpoint_size;
}

static void
zdb_leak_init_exclude_checkpoint(spa_t *spa, zdb_cb_t *zcb)
{
	ASSERT(!dump_opt['L']);

	vdev_t *rvd = spa->spa_root_vdev;
	for (uint64_t c = 0; c < rvd->vdev_children; c++) {
		ASSERT3U(c, ==, rvd->vdev_child[c]->vdev_id);
		zdb_leak_init_vdev_exclude_checkpoint(rvd->vdev_child[c], zcb);
	}
}

static int
count_unflushed_space_cb(spa_t *spa, space_map_entry_t *sme,
    uint64_t txg, void *arg)
{
	int64_t *ualloc_space = arg;

	uint64_t offset = sme->sme_offset;
	uint64_t vdev_id = sme->sme_vdev;

	vdev_t *vd = vdev_lookup_top(spa, vdev_id);
	if (!vdev_is_concrete(vd))
		return (0);

	metaslab_t *ms = vd->vdev_ms[offset >> vd->vdev_ms_shift];
	ASSERT(sme->sme_type == SM_ALLOC || sme->sme_type == SM_FREE);

	if (txg < metaslab_unflushed_txg(ms))
		return (0);

	if (sme->sme_type == SM_ALLOC)
		*ualloc_space += sme->sme_run;
	else
		*ualloc_space -= sme->sme_run;

	return (0);
}

static int64_t
get_unflushed_alloc_space(spa_t *spa)
{
	if (dump_opt['L'])
		return (0);

	int64_t ualloc_space = 0;
	iterate_through_spacemap_logs(spa, count_unflushed_space_cb,
	    &ualloc_space);
	return (ualloc_space);
}

static int
load_unflushed_cb(spa_t *spa, space_map_entry_t *sme, uint64_t txg, void *arg)
{
	maptype_t *uic_maptype = arg;

	uint64_t offset = sme->sme_offset;
	uint64_t size = sme->sme_run;
	uint64_t vdev_id = sme->sme_vdev;

	vdev_t *vd = vdev_lookup_top(spa, vdev_id);

	/* skip indirect vdevs */
	if (!vdev_is_concrete(vd))
		return (0);

	metaslab_t *ms = vd->vdev_ms[offset >> vd->vdev_ms_shift];

	ASSERT(sme->sme_type == SM_ALLOC || sme->sme_type == SM_FREE);
	ASSERT(*uic_maptype == SM_ALLOC || *uic_maptype == SM_FREE);

	if (txg < metaslab_unflushed_txg(ms))
		return (0);

	if (*uic_maptype == sme->sme_type)
		zfs_range_tree_add(ms->ms_allocatable, offset, size);
	else
		zfs_range_tree_remove(ms->ms_allocatable, offset, size);

	return (0);
}

static void
load_unflushed_to_ms_allocatables(spa_t *spa, maptype_t maptype)
{
	iterate_through_spacemap_logs(spa, load_unflushed_cb, &maptype);
}

static void
load_concrete_ms_allocatable_trees(spa_t *spa, maptype_t maptype)
{
	vdev_t *rvd = spa->spa_root_vdev;
	for (uint64_t i = 0; i < rvd->vdev_children; i++) {
		vdev_t *vd = rvd->vdev_child[i];

		ASSERT3U(i, ==, vd->vdev_id);

		if (vd->vdev_ops == &vdev_indirect_ops)
			continue;

		for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {
			metaslab_t *msp = vd->vdev_ms[m];

			(void) fprintf(stderr,
			    "\rloading concrete vdev %llu, "
			    "metaslab %llu of %llu ...",
			    (longlong_t)vd->vdev_id,
			    (longlong_t)msp->ms_id,
			    (longlong_t)vd->vdev_ms_count);

			mutex_enter(&msp->ms_lock);
			zfs_range_tree_vacate(msp->ms_allocatable, NULL, NULL);

			/*
			 * We don't want to spend the CPU manipulating the
			 * size-ordered tree, so clear the range_tree ops.
			 */
			msp->ms_allocatable->rt_ops = NULL;

			if (msp->ms_sm != NULL) {
				VERIFY0(space_map_load(msp->ms_sm,
				    msp->ms_allocatable, maptype));
			}
			if (!msp->ms_loaded)
				msp->ms_loaded = B_TRUE;
			mutex_exit(&msp->ms_lock);
		}
	}

	load_unflushed_to_ms_allocatables(spa, maptype);
}

/*
 * vm_idxp is an in-out parameter which (for indirect vdevs) is the
 * index in vim_entries that has the first entry in this metaslab.
 * On return, it will be set to the first entry after this metaslab.
 */
static void
load_indirect_ms_allocatable_tree(vdev_t *vd, metaslab_t *msp,
    uint64_t *vim_idxp)
{
	vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;

	mutex_enter(&msp->ms_lock);
	zfs_range_tree_vacate(msp->ms_allocatable, NULL, NULL);

	/*
	 * We don't want to spend the CPU manipulating the
	 * size-ordered tree, so clear the range_tree ops.
	 */
	msp->ms_allocatable->rt_ops = NULL;

	for (; *vim_idxp < vdev_indirect_mapping_num_entries(vim);
	    (*vim_idxp)++) {
		vdev_indirect_mapping_entry_phys_t *vimep =
		    &vim->vim_entries[*vim_idxp];
		uint64_t ent_offset = DVA_MAPPING_GET_SRC_OFFSET(vimep);
		uint64_t ent_len = DVA_GET_ASIZE(&vimep->vimep_dst);
		ASSERT3U(ent_offset, >=, msp->ms_start);
		if (ent_offset >= msp->ms_start + msp->ms_size)
			break;

		/*
		 * Mappings do not cross metaslab boundaries,
		 * because we create them by walking the metaslabs.
		 */
		ASSERT3U(ent_offset + ent_len, <=,
		    msp->ms_start + msp->ms_size);
		zfs_range_tree_add(msp->ms_allocatable, ent_offset, ent_len);
	}

	if (!msp->ms_loaded)
		msp->ms_loaded = B_TRUE;
	mutex_exit(&msp->ms_lock);
}

static void
zdb_leak_init_prepare_indirect_vdevs(spa_t *spa, zdb_cb_t *zcb)
{
	ASSERT(!dump_opt['L']);

	vdev_t *rvd = spa->spa_root_vdev;
	for (uint64_t c = 0; c < rvd->vdev_children; c++) {
		vdev_t *vd = rvd->vdev_child[c];

		ASSERT3U(c, ==, vd->vdev_id);

		if (vd->vdev_ops != &vdev_indirect_ops)
			continue;

		/*
		 * Note: we don't check for mapping leaks on
		 * removing vdevs because their ms_allocatable's
		 * are used to look for leaks in allocated space.
		 */
		zcb->zcb_vd_obsolete_counts[c] = zdb_load_obsolete_counts(vd);

		/*
		 * Normally, indirect vdevs don't have any
		 * metaslabs.  We want to set them up for
		 * zio_claim().
		 */
		vdev_metaslab_group_create(vd);
		VERIFY0(vdev_metaslab_init(vd, 0));

		vdev_indirect_mapping_t *vim __maybe_unused =
		    vd->vdev_indirect_mapping;
		uint64_t vim_idx = 0;
		for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {

			(void) fprintf(stderr,
			    "\rloading indirect vdev %llu, "
			    "metaslab %llu of %llu ...",
			    (longlong_t)vd->vdev_id,
			    (longlong_t)vd->vdev_ms[m]->ms_id,
			    (longlong_t)vd->vdev_ms_count);

			load_indirect_ms_allocatable_tree(vd, vd->vdev_ms[m],
			    &vim_idx);
		}
		ASSERT3U(vim_idx, ==, vdev_indirect_mapping_num_entries(vim));
	}
}

static void
zdb_leak_init(spa_t *spa, zdb_cb_t *zcb)
{
	zcb->zcb_spa = spa;

	if (dump_opt['L'])
		return;

	dsl_pool_t *dp = spa->spa_dsl_pool;
	vdev_t *rvd = spa->spa_root_vdev;

	/*
	 * We are going to be changing the meaning of the metaslab's
	 * ms_allocatable.  Ensure that the allocator doesn't try to
	 * use the tree.
	 */
	spa->spa_normal_class->mc_ops = &zdb_metaslab_ops;
	spa->spa_log_class->mc_ops = &zdb_metaslab_ops;
	spa->spa_embedded_log_class->mc_ops = &zdb_metaslab_ops;
	spa->spa_special_embedded_log_class->mc_ops = &zdb_metaslab_ops;

	zcb->zcb_vd_obsolete_counts =
	    umem_zalloc(rvd->vdev_children * sizeof (uint32_t *),
	    UMEM_NOFAIL);

	/*
	 * For leak detection, we overload the ms_allocatable trees
	 * to contain allocated segments instead of free segments.
	 * As a result, we can't use the normal metaslab_load/unload
	 * interfaces.
	 */
	zdb_leak_init_prepare_indirect_vdevs(spa, zcb);
	load_concrete_ms_allocatable_trees(spa, SM_ALLOC);

	/*
	 * On load_concrete_ms_allocatable_trees() we loaded all the
	 * allocated entries from the ms_sm to the ms_allocatable for
	 * each metaslab. If the pool has a checkpoint or is in the
	 * middle of discarding a checkpoint, some of these blocks
	 * may have been freed but their ms_sm may not have been
	 * updated because they are referenced by the checkpoint. In
	 * order to avoid false-positives during leak-detection, we
	 * go through the vdev's checkpoint space map and exclude all
	 * its entries from their relevant ms_allocatable.
	 *
	 * We also aggregate the space held by the checkpoint and add
	 * it to zcb_checkpoint_size.
	 *
	 * Note that at this point we are also verifying that all the
	 * entries on the checkpoint_sm are marked as allocated in
	 * the ms_sm of their relevant metaslab.
	 * [see comment in checkpoint_sm_exclude_entry_cb()]
	 */
	zdb_leak_init_exclude_checkpoint(spa, zcb);
	ASSERT3U(zcb->zcb_checkpoint_size, ==, spa_get_checkpoint_space(spa));

	/* for cleaner progress output */
	(void) fprintf(stderr, "\n");

	if (bpobj_is_open(&dp->dp_obsolete_bpobj)) {
		ASSERT(spa_feature_is_enabled(spa,
		    SPA_FEATURE_DEVICE_REMOVAL));
		(void) bpobj_iterate_nofree(&dp->dp_obsolete_bpobj,
		    increment_indirect_mapping_cb, zcb, NULL);
	}
}

static boolean_t
zdb_check_for_obsolete_leaks(vdev_t *vd, zdb_cb_t *zcb)
{
	boolean_t leaks = B_FALSE;
	vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;
	uint64_t total_leaked = 0;
	boolean_t are_precise = B_FALSE;

	ASSERT(vim != NULL);

	for (uint64_t i = 0; i < vdev_indirect_mapping_num_entries(vim); i++) {
		vdev_indirect_mapping_entry_phys_t *vimep =
		    &vim->vim_entries[i];
		uint64_t obsolete_bytes = 0;
		uint64_t offset = DVA_MAPPING_GET_SRC_OFFSET(vimep);
		metaslab_t *msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];

		/*
		 * This is not very efficient but it's easy to
		 * verify correctness.
		 */
		for (uint64_t inner_offset = 0;
		    inner_offset < DVA_GET_ASIZE(&vimep->vimep_dst);
		    inner_offset += 1ULL << vd->vdev_ashift) {
			if (zfs_range_tree_contains(msp->ms_allocatable,
			    offset + inner_offset, 1ULL << vd->vdev_ashift)) {
				obsolete_bytes += 1ULL << vd->vdev_ashift;
			}
		}

		int64_t bytes_leaked = obsolete_bytes -
		    zcb->zcb_vd_obsolete_counts[vd->vdev_id][i];
		ASSERT3U(DVA_GET_ASIZE(&vimep->vimep_dst), >=,
		    zcb->zcb_vd_obsolete_counts[vd->vdev_id][i]);

		VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise));
		if (bytes_leaked != 0 && (are_precise || dump_opt['d'] >= 5)) {
			(void) printf("obsolete indirect mapping count "
			    "mismatch on %llu:%llx:%llx : %llx bytes leaked\n",
			    (u_longlong_t)vd->vdev_id,
			    (u_longlong_t)DVA_MAPPING_GET_SRC_OFFSET(vimep),
			    (u_longlong_t)DVA_GET_ASIZE(&vimep->vimep_dst),
			    (u_longlong_t)bytes_leaked);
		}
		total_leaked += ABS(bytes_leaked);
	}

	VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise));
	if (!are_precise && total_leaked > 0) {
		int pct_leaked = total_leaked * 100 /
		    vdev_indirect_mapping_bytes_mapped(vim);
		(void) printf("cannot verify obsolete indirect mapping "
		    "counts of vdev %llu because precise feature was not "
		    "enabled when it was removed: %d%% (%llx bytes) of mapping"
		    "unreferenced\n",
		    (u_longlong_t)vd->vdev_id, pct_leaked,
		    (u_longlong_t)total_leaked);
	} else if (total_leaked > 0) {
		(void) printf("obsolete indirect mapping count mismatch "
		    "for vdev %llu -- %llx total bytes mismatched\n",
		    (u_longlong_t)vd->vdev_id,
		    (u_longlong_t)total_leaked);
		leaks |= B_TRUE;
	}

	vdev_indirect_mapping_free_obsolete_counts(vim,
	    zcb->zcb_vd_obsolete_counts[vd->vdev_id]);
	zcb->zcb_vd_obsolete_counts[vd->vdev_id] = NULL;

	return (leaks);
}

static boolean_t
zdb_leak_fini(spa_t *spa, zdb_cb_t *zcb)
{
	if (dump_opt['L'])
		return (B_FALSE);

	boolean_t leaks = B_FALSE;
	vdev_t *rvd = spa->spa_root_vdev;
	for (unsigned c = 0; c < rvd->vdev_children; c++) {
		vdev_t *vd = rvd->vdev_child[c];

		if (zcb->zcb_vd_obsolete_counts[c] != NULL) {
			leaks |= zdb_check_for_obsolete_leaks(vd, zcb);
		}

		for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {
			metaslab_t *msp = vd->vdev_ms[m];
			ASSERT3P(msp->ms_group, ==, (msp->ms_group->mg_class ==
			    spa_embedded_log_class(spa) ||
			    msp->ms_group->mg_class ==
			    spa_special_embedded_log_class(spa)) ?
			    vd->vdev_log_mg : vd->vdev_mg);

			/*
			 * ms_allocatable has been overloaded
			 * to contain allocated segments. Now that
			 * we finished traversing all blocks, any
			 * block that remains in the ms_allocatable
			 * represents an allocated block that we
			 * did not claim during the traversal.
			 * Claimed blocks would have been removed
			 * from the ms_allocatable.  For indirect
			 * vdevs, space remaining in the tree
			 * represents parts of the mapping that are
			 * not referenced, which is not a bug.
			 */
			if (vd->vdev_ops == &vdev_indirect_ops) {
				zfs_range_tree_vacate(msp->ms_allocatable,
				    NULL, NULL);
			} else {
				zfs_range_tree_vacate(msp->ms_allocatable,
				    zdb_leak, vd);
			}
			if (msp->ms_loaded) {
				msp->ms_loaded = B_FALSE;
			}
		}
	}

	umem_free(zcb->zcb_vd_obsolete_counts,
	    rvd->vdev_children * sizeof (uint32_t *));
	zcb->zcb_vd_obsolete_counts = NULL;

	return (leaks);
}

static int
count_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
{
	(void) tx;
	zdb_cb_t *zcb = arg;

	if (dump_opt['b'] >= 5) {
		char blkbuf[BP_SPRINTF_LEN];
		snprintf_blkptr(blkbuf, sizeof (blkbuf), bp);
		(void) printf("[%s] %s\n",
		    "deferred free", blkbuf);
	}
	zdb_count_block(zcb, NULL, bp, ZDB_OT_DEFERRED);
	return (0);
}

/*
 * Iterate over livelists which have been destroyed by the user but
 * are still present in the MOS, waiting to be freed
 */
static void
iterate_deleted_livelists(spa_t *spa, ll_iter_t func, void *arg)
{
	objset_t *mos = spa->spa_meta_objset;
	uint64_t zap_obj;
	int err = zap_lookup(mos, DMU_POOL_DIRECTORY_OBJECT,
	    DMU_POOL_DELETED_CLONES, sizeof (uint64_t), 1, &zap_obj);
	if (err == ENOENT)
		return;
	ASSERT0(err);

	zap_cursor_t zc;
	zap_attribute_t *attrp = zap_attribute_alloc();
	dsl_deadlist_t ll;
	/* NULL out os prior to dsl_deadlist_open in case it's garbage */
	ll.dl_os = NULL;
	for (zap_cursor_init(&zc, mos, zap_obj);
	    zap_cursor_retrieve(&zc, attrp) == 0;
	    (void) zap_cursor_advance(&zc)) {
		VERIFY0(dsl_deadlist_open(&ll, mos, attrp->za_first_integer));
		func(&ll, arg);
		dsl_deadlist_close(&ll);
	}
	zap_cursor_fini(&zc);
	zap_attribute_free(attrp);
}

static int
bpobj_count_block_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
    dmu_tx_t *tx)
{
	ASSERT(!bp_freed);
	return (count_block_cb(arg, bp, tx));
}

static int
livelist_entry_count_blocks_cb(void *args, dsl_deadlist_entry_t *dle)
{
	zdb_cb_t *zbc = args;
	bplist_t blks;
	bplist_create(&blks);
	/* determine which blocks have been alloc'd but not freed */
	VERIFY0(dsl_process_sub_livelist(&dle->dle_bpobj, &blks, NULL, NULL));
	/* count those blocks */
	(void) bplist_iterate(&blks, count_block_cb, zbc, NULL);
	bplist_destroy(&blks);
	return (0);
}

static void
livelist_count_blocks(dsl_deadlist_t *ll, void *arg)
{
	dsl_deadlist_iterate(ll, livelist_entry_count_blocks_cb, arg);
}

/*
 * Count the blocks in the livelists that have been destroyed by the user
 * but haven't yet been freed.
 */
static void
deleted_livelists_count_blocks(spa_t *spa, zdb_cb_t *zbc)
{
	iterate_deleted_livelists(spa, livelist_count_blocks, zbc);
}

static void
dump_livelist_cb(dsl_deadlist_t *ll, void *arg)
{
	ASSERT0P(arg);
	global_feature_count[SPA_FEATURE_LIVELIST]++;
	dump_blkptr_list(ll, "Deleted Livelist");
	dsl_deadlist_iterate(ll, sublivelist_verify_lightweight, NULL);
}

/*
 * Print out, register object references to, and increment feature counts for
 * livelists that have been destroyed by the user but haven't yet been freed.
 */
static void
deleted_livelists_dump_mos(spa_t *spa)
{
	uint64_t zap_obj;
	objset_t *mos = spa->spa_meta_objset;
	int err = zap_lookup(mos, DMU_POOL_DIRECTORY_OBJECT,
	    DMU_POOL_DELETED_CLONES, sizeof (uint64_t), 1, &zap_obj);
	if (err == ENOENT)
		return;
	mos_obj_refd(zap_obj);
	iterate_deleted_livelists(spa, dump_livelist_cb, NULL);
}

static int
zdb_brt_entry_compare(const void *zcn1, const void *zcn2)
{
	const dva_t *dva1 = &((const zdb_brt_entry_t *)zcn1)->zbre_dva;
	const dva_t *dva2 = &((const zdb_brt_entry_t *)zcn2)->zbre_dva;
	int cmp;

	cmp = TREE_CMP(DVA_GET_VDEV(dva1), DVA_GET_VDEV(dva2));
	if (cmp == 0)
		cmp = TREE_CMP(DVA_GET_OFFSET(dva1), DVA_GET_OFFSET(dva2));

	return (cmp);
}

static int
dump_block_stats(spa_t *spa)
{
	zdb_cb_t *zcb;
	zdb_blkstats_t *zb, *tzb;
	uint64_t norm_alloc, norm_space, total_alloc, total_found;
	int flags = TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA |
	    TRAVERSE_NO_DECRYPT | TRAVERSE_HARD;
	boolean_t leaks = B_FALSE;
	int e, c, err;
	bp_embedded_type_t i;

	ddt_prefetch_all(spa);

	zcb = umem_zalloc(sizeof (zdb_cb_t), UMEM_NOFAIL);

	if (spa_feature_is_active(spa, SPA_FEATURE_BLOCK_CLONING)) {
		avl_create(&zcb->zcb_brt, zdb_brt_entry_compare,
		    sizeof (zdb_brt_entry_t),
		    offsetof(zdb_brt_entry_t, zbre_node));
		zcb->zcb_brt_is_active = B_TRUE;
	}

	(void) printf("\nTraversing all blocks %s%s%s%s%s...\n\n",
	    (dump_opt['c'] || !dump_opt['L']) ? "to verify " : "",
	    (dump_opt['c'] == 1) ? "metadata " : "",
	    dump_opt['c'] ? "checksums " : "",
	    (dump_opt['c'] && !dump_opt['L']) ? "and verify " : "",
	    !dump_opt['L'] ? "nothing leaked " : "");

	/*
	 * When leak detection is enabled we load all space maps as SM_ALLOC
	 * maps, then traverse the pool claiming each block we discover. If
	 * the pool is perfectly consistent, the segment trees will be empty
	 * when we're done. Anything left over is a leak; any block we can't
	 * claim (because it's not part of any space map) is a double
	 * allocation, reference to a freed block, or an unclaimed log block.
	 *
	 * When leak detection is disabled (-L option) we still traverse the
	 * pool claiming each block we discover, but we skip opening any space
	 * maps.
	 */
	zdb_leak_init(spa, zcb);

	/*
	 * If there's a deferred-free bplist, process that first.
	 */
	(void) bpobj_iterate_nofree(&spa->spa_deferred_bpobj,
	    bpobj_count_block_cb, zcb, NULL);

	if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
		(void) bpobj_iterate_nofree(&spa->spa_dsl_pool->dp_free_bpobj,
		    bpobj_count_block_cb, zcb, NULL);
	}

	zdb_claim_removing(spa, zcb);

	if (spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) {
		VERIFY3U(0, ==, bptree_iterate(spa->spa_meta_objset,
		    spa->spa_dsl_pool->dp_bptree_obj, B_FALSE, count_block_cb,
		    zcb, NULL));
	}

	deleted_livelists_count_blocks(spa, zcb);

	if (dump_opt['c'] > 1)
		flags |= TRAVERSE_PREFETCH_DATA;

	zcb->zcb_totalasize = metaslab_class_get_alloc(spa_normal_class(spa));
	zcb->zcb_totalasize += metaslab_class_get_alloc(spa_special_class(spa));
	zcb->zcb_totalasize += metaslab_class_get_alloc(spa_dedup_class(spa));
	zcb->zcb_totalasize +=
	    metaslab_class_get_alloc(spa_embedded_log_class(spa));
	zcb->zcb_totalasize +=
	    metaslab_class_get_alloc(spa_special_embedded_log_class(spa));
	zcb->zcb_start = zcb->zcb_lastprint = gethrtime();
	err = traverse_pool(spa, 0, flags, zdb_blkptr_cb, zcb);

	/*
	 * If we've traversed the data blocks then we need to wait for those
	 * I/Os to complete. We leverage "The Godfather" zio to wait on
	 * all async I/Os to complete.
	 */
	if (dump_opt['c']) {
		for (c = 0; c < max_ncpus; c++) {
			(void) zio_wait(spa->spa_async_zio_root[c]);
			spa->spa_async_zio_root[c] = zio_root(spa, NULL, NULL,
			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
			    ZIO_FLAG_GODFATHER);
		}
	}
	ASSERT0(spa->spa_load_verify_bytes);

	/*
	 * Done after zio_wait() since zcb_haderrors is modified in
	 * zdb_blkptr_done()
	 */
	zcb->zcb_haderrors |= err;

	if (zcb->zcb_haderrors) {
		(void) printf("\nError counts:\n\n");
		(void) printf("\t%5s  %s\n", "errno", "count");
		for (e = 0; e < 256; e++) {
			if (zcb->zcb_errors[e] != 0) {
				(void) printf("\t%5d  %llu\n",
				    e, (u_longlong_t)zcb->zcb_errors[e]);
			}
		}
	}

	/*
	 * Report any leaked segments.
	 */
	leaks |= zdb_leak_fini(spa, zcb);

	tzb = &zcb->zcb_type[ZB_TOTAL][ZDB_OT_TOTAL];

	norm_alloc = metaslab_class_get_alloc(spa_normal_class(spa));
	norm_space = metaslab_class_get_space(spa_normal_class(spa));

	total_alloc = norm_alloc +
	    metaslab_class_get_alloc(spa_log_class(spa)) +
	    metaslab_class_get_alloc(spa_embedded_log_class(spa)) +
	    metaslab_class_get_alloc(spa_special_embedded_log_class(spa)) +
	    metaslab_class_get_alloc(spa_special_class(spa)) +
	    metaslab_class_get_alloc(spa_dedup_class(spa)) +
	    get_unflushed_alloc_space(spa);
	total_found =
	    tzb->zb_asize - zcb->zcb_dedup_asize - zcb->zcb_clone_asize +
	    zcb->zcb_removing_size + zcb->zcb_checkpoint_size;

	if (total_found == total_alloc && !dump_opt['L']) {
		(void) printf("\n\tNo leaks (block sum matches space"
		    " maps exactly)\n");
	} else if (!dump_opt['L']) {
		(void) printf("block traversal size %llu != alloc %llu "
		    "(%s %lld)\n",
		    (u_longlong_t)total_found,
		    (u_longlong_t)total_alloc,
		    (dump_opt['L']) ? "unreachable" : "leaked",
		    (longlong_t)(total_alloc - total_found));
	}

	if (tzb->zb_count == 0) {
		umem_free(zcb, sizeof (zdb_cb_t));
		return (2);
	}

	(void) printf("\n");
	(void) printf("\t%-16s %14llu\n", "bp count:",
	    (u_longlong_t)tzb->zb_count);
	(void) printf("\t%-16s %14llu\n", "ganged count:",
	    (longlong_t)tzb->zb_gangs);
	(void) printf("\t%-16s %14llu      avg: %6llu\n", "bp logical:",
	    (u_longlong_t)tzb->zb_lsize,
	    (u_longlong_t)(tzb->zb_lsize / tzb->zb_count));
	(void) printf("\t%-16s %14llu      avg: %6llu     compression: %6.2f\n",
	    "bp physical:", (u_longlong_t)tzb->zb_psize,
	    (u_longlong_t)(tzb->zb_psize / tzb->zb_count),
	    (double)tzb->zb_lsize / tzb->zb_psize);
	(void) printf("\t%-16s %14llu      avg: %6llu     compression: %6.2f\n",
	    "bp allocated:", (u_longlong_t)tzb->zb_asize,
	    (u_longlong_t)(tzb->zb_asize / tzb->zb_count),
	    (double)tzb->zb_lsize / tzb->zb_asize);
	(void) printf("\t%-16s %14llu    ref>1: %6llu   deduplication: %6.2f\n",
	    "bp deduped:", (u_longlong_t)zcb->zcb_dedup_asize,
	    (u_longlong_t)zcb->zcb_dedup_blocks,
	    (double)zcb->zcb_dedup_asize / tzb->zb_asize + 1.0);
	(void) printf("\t%-16s %14llu    count: %6llu\n",
	    "bp cloned:", (u_longlong_t)zcb->zcb_clone_asize,
	    (u_longlong_t)zcb->zcb_clone_blocks);
	(void) printf("\t%-16s %14llu     used: %5.2f%%\n", "Normal class:",
	    (u_longlong_t)norm_alloc, 100.0 * norm_alloc / norm_space);

	if (spa_special_class(spa)->mc_allocator[0].mca_rotor != NULL) {
		uint64_t alloc = metaslab_class_get_alloc(
		    spa_special_class(spa));
		uint64_t space = metaslab_class_get_space(
		    spa_special_class(spa));

		(void) printf("\t%-16s %14llu     used: %5.2f%%\n",
		    "Special class", (u_longlong_t)alloc,
		    100.0 * alloc / space);
	}

	if (spa_dedup_class(spa)->mc_allocator[0].mca_rotor != NULL) {
		uint64_t alloc = metaslab_class_get_alloc(
		    spa_dedup_class(spa));
		uint64_t space = metaslab_class_get_space(
		    spa_dedup_class(spa));

		(void) printf("\t%-16s %14llu     used: %5.2f%%\n",
		    "Dedup class", (u_longlong_t)alloc,
		    100.0 * alloc / space);
	}

	if (spa_embedded_log_class(spa)->mc_allocator[0].mca_rotor != NULL) {
		uint64_t alloc = metaslab_class_get_alloc(
		    spa_embedded_log_class(spa));
		uint64_t space = metaslab_class_get_space(
		    spa_embedded_log_class(spa));

		(void) printf("\t%-16s %14llu     used: %5.2f%%\n",
		    "Embedded log class", (u_longlong_t)alloc,
		    100.0 * alloc / space);
	}

	if (spa_special_embedded_log_class(spa)->mc_allocator[0].mca_rotor
	    != NULL) {
		uint64_t alloc = metaslab_class_get_alloc(
		    spa_special_embedded_log_class(spa));
		uint64_t space = metaslab_class_get_space(
		    spa_special_embedded_log_class(spa));

		(void) printf("\t%-16s %14llu     used: %5.2f%%\n",
		    "Special embedded log", (u_longlong_t)alloc,
		    100.0 * alloc / space);
	}

	for (i = 0; i < NUM_BP_EMBEDDED_TYPES; i++) {
		if (zcb->zcb_embedded_blocks[i] == 0)
			continue;
		(void) printf("\n");
		(void) printf("\tadditional, non-pointer bps of type %u: "
		    "%10llu\n",
		    i, (u_longlong_t)zcb->zcb_embedded_blocks[i]);

		if (dump_opt['b'] >= 3) {
			(void) printf("\t number of (compressed) bytes:  "
			    "number of bps\n");
			dump_histogram(zcb->zcb_embedded_histogram[i],
			    sizeof (zcb->zcb_embedded_histogram[i]) /
			    sizeof (zcb->zcb_embedded_histogram[i][0]), 0);
		}
	}

	if (tzb->zb_ditto_samevdev != 0) {
		(void) printf("\tDittoed blocks on same vdev: %llu\n",
		    (longlong_t)tzb->zb_ditto_samevdev);
	}
	if (tzb->zb_ditto_same_ms != 0) {
		(void) printf("\tDittoed blocks in same metaslab: %llu\n",
		    (longlong_t)tzb->zb_ditto_same_ms);
	}

	for (uint64_t v = 0; v < spa->spa_root_vdev->vdev_children; v++) {
		vdev_t *vd = spa->spa_root_vdev->vdev_child[v];
		vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;

		if (vim == NULL) {
			continue;
		}

		char mem[32];
		zdb_nicenum(vdev_indirect_mapping_num_entries(vim),
		    mem, vdev_indirect_mapping_size(vim));

		(void) printf("\tindirect vdev id %llu has %llu segments "
		    "(%s in memory)\n",
		    (longlong_t)vd->vdev_id,
		    (longlong_t)vdev_indirect_mapping_num_entries(vim), mem);
	}

	if (dump_opt['b'] >= 2) {
		int l, t, level;
		char csize[32], lsize[32], psize[32], asize[32];
		char avg[32], gang[32];
		(void) printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
		    "\t  avg\t comp\t%%Total\tType\n");

		zfs_blkstat_t *mdstats = umem_zalloc(sizeof (zfs_blkstat_t),
		    UMEM_NOFAIL);

		for (t = 0; t <= ZDB_OT_TOTAL; t++) {
			const char *typename;

			/* make sure nicenum has enough space */
			_Static_assert(sizeof (csize) >= NN_NUMBUF_SZ,
			    "csize truncated");
			_Static_assert(sizeof (lsize) >= NN_NUMBUF_SZ,
			    "lsize truncated");
			_Static_assert(sizeof (psize) >= NN_NUMBUF_SZ,
			    "psize truncated");
			_Static_assert(sizeof (asize) >= NN_NUMBUF_SZ,
			    "asize truncated");
			_Static_assert(sizeof (avg) >= NN_NUMBUF_SZ,
			    "avg truncated");
			_Static_assert(sizeof (gang) >= NN_NUMBUF_SZ,
			    "gang truncated");

			if (t < DMU_OT_NUMTYPES)
				typename = dmu_ot[t].ot_name;
			else
				typename = zdb_ot_extname[t - DMU_OT_NUMTYPES];

			if (zcb->zcb_type[ZB_TOTAL][t].zb_asize == 0) {
				(void) printf("%6s\t%5s\t%5s\t%5s"
				    "\t%5s\t%5s\t%6s\t%s\n",
				    "-",
				    "-",
				    "-",
				    "-",
				    "-",
				    "-",
				    "-",
				    typename);
				continue;
			}

			for (l = ZB_TOTAL - 1; l >= -1; l--) {
				level = (l == -1 ? ZB_TOTAL : l);
				zb = &zcb->zcb_type[level][t];

				if (zb->zb_asize == 0)
					continue;

				if (level != ZB_TOTAL && t < DMU_OT_NUMTYPES &&
				    (level > 0 || DMU_OT_IS_METADATA(t))) {
					mdstats->zb_count += zb->zb_count;
					mdstats->zb_lsize += zb->zb_lsize;
					mdstats->zb_psize += zb->zb_psize;
					mdstats->zb_asize += zb->zb_asize;
					mdstats->zb_gangs += zb->zb_gangs;
				}

				if (dump_opt['b'] < 3 && level != ZB_TOTAL)
					continue;

				if (level == 0 && zb->zb_asize ==
				    zcb->zcb_type[ZB_TOTAL][t].zb_asize)
					continue;

				zdb_nicenum(zb->zb_count, csize,
				    sizeof (csize));
				zdb_nicenum(zb->zb_lsize, lsize,
				    sizeof (lsize));
				zdb_nicenum(zb->zb_psize, psize,
				    sizeof (psize));
				zdb_nicenum(zb->zb_asize, asize,
				    sizeof (asize));
				zdb_nicenum(zb->zb_asize / zb->zb_count, avg,
				    sizeof (avg));
				zdb_nicenum(zb->zb_gangs, gang, sizeof (gang));

				(void) printf("%6s\t%5s\t%5s\t%5s\t%5s"
				    "\t%5.2f\t%6.2f\t",
				    csize, lsize, psize, asize, avg,
				    (double)zb->zb_lsize / zb->zb_psize,
				    100.0 * zb->zb_asize / tzb->zb_asize);

				if (level == ZB_TOTAL)
					(void) printf("%s\n", typename);
				else
					(void) printf("    L%d %s\n",
					    level, typename);

				if (dump_opt['b'] >= 3 && zb->zb_gangs > 0) {
					(void) printf("\t number of ganged "
					    "blocks: %s\n", gang);
				}

				if (dump_opt['b'] >= 4) {
					(void) printf("psize "
					    "(in 512-byte sectors): "
					    "number of blocks\n");
					dump_histogram(zb->zb_psize_histogram,
					    PSIZE_HISTO_SIZE, 0);
				}
			}
		}
		zdb_nicenum(mdstats->zb_count, csize,
		    sizeof (csize));
		zdb_nicenum(mdstats->zb_lsize, lsize,
		    sizeof (lsize));
		zdb_nicenum(mdstats->zb_psize, psize,
		    sizeof (psize));
		zdb_nicenum(mdstats->zb_asize, asize,
		    sizeof (asize));
		zdb_nicenum(mdstats->zb_asize / mdstats->zb_count, avg,
		    sizeof (avg));
		zdb_nicenum(mdstats->zb_gangs, gang, sizeof (gang));

		(void) printf("%6s\t%5s\t%5s\t%5s\t%5s"
		    "\t%5.2f\t%6.2f\t",
		    csize, lsize, psize, asize, avg,
		    (double)mdstats->zb_lsize / mdstats->zb_psize,
		    100.0 * mdstats->zb_asize / tzb->zb_asize);
		(void) printf("%s\n", "Metadata Total");

		/* Output a table summarizing block sizes in the pool */
		if (dump_opt['b'] >= 2) {
			dump_size_histograms(zcb);
		}

		umem_free(mdstats, sizeof (zfs_blkstat_t));
	}

	(void) printf("\n");

	if (leaks) {
		umem_free(zcb, sizeof (zdb_cb_t));
		return (2);
	}

	if (zcb->zcb_haderrors) {
		umem_free(zcb, sizeof (zdb_cb_t));
		return (3);
	}

	umem_free(zcb, sizeof (zdb_cb_t));
	return (0);
}

typedef struct zdb_ddt_entry {
	/* key must be first for ddt_key_compare */
	ddt_key_t	zdde_key;
	uint64_t	zdde_ref_blocks;
	uint64_t	zdde_ref_lsize;
	uint64_t	zdde_ref_psize;
	uint64_t	zdde_ref_dsize;
	avl_node_t	zdde_node;
} zdb_ddt_entry_t;

static int
zdb_ddt_add_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
    const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
{
	(void) zilog, (void) dnp;
	avl_tree_t *t = arg;
	avl_index_t where;
	zdb_ddt_entry_t *zdde, zdde_search;

	if (zb->zb_level == ZB_DNODE_LEVEL || BP_IS_HOLE(bp) ||
	    BP_IS_EMBEDDED(bp))
		return (0);

	if (dump_opt['S'] > 1 && zb->zb_level == ZB_ROOT_LEVEL) {
		(void) printf("traversing objset %llu, %llu objects, "
		    "%lu blocks so far\n",
		    (u_longlong_t)zb->zb_objset,
		    (u_longlong_t)BP_GET_FILL(bp),
		    avl_numnodes(t));
	}

	if (BP_IS_HOLE(bp) || BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_OFF ||
	    BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))
		return (0);

	ddt_key_fill(&zdde_search.zdde_key, bp);

	zdde = avl_find(t, &zdde_search, &where);

	if (zdde == NULL) {
		zdde = umem_zalloc(sizeof (*zdde), UMEM_NOFAIL);
		zdde->zdde_key = zdde_search.zdde_key;
		avl_insert(t, zdde, where);
	}

	zdde->zdde_ref_blocks += 1;
	zdde->zdde_ref_lsize += BP_GET_LSIZE(bp);
	zdde->zdde_ref_psize += BP_GET_PSIZE(bp);
	zdde->zdde_ref_dsize += bp_get_dsize_sync(spa, bp);

	return (0);
}

static void
dump_simulated_ddt(spa_t *spa)
{
	avl_tree_t t;
	void *cookie = NULL;
	zdb_ddt_entry_t *zdde;
	ddt_histogram_t ddh_total = {{{0}}};
	ddt_stat_t dds_total = {0};

	avl_create(&t, ddt_key_compare,
	    sizeof (zdb_ddt_entry_t), offsetof(zdb_ddt_entry_t, zdde_node));

	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);

	(void) traverse_pool(spa, 0, TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA |
	    TRAVERSE_NO_DECRYPT, zdb_ddt_add_cb, &t);

	spa_config_exit(spa, SCL_CONFIG, FTAG);

	while ((zdde = avl_destroy_nodes(&t, &cookie)) != NULL) {
		uint64_t refcnt = zdde->zdde_ref_blocks;
		ASSERT(refcnt != 0);

		ddt_stat_t *dds = &ddh_total.ddh_stat[highbit64(refcnt) - 1];

		dds->dds_blocks += zdde->zdde_ref_blocks / refcnt;
		dds->dds_lsize += zdde->zdde_ref_lsize / refcnt;
		dds->dds_psize += zdde->zdde_ref_psize / refcnt;
		dds->dds_dsize += zdde->zdde_ref_dsize / refcnt;

		dds->dds_ref_blocks += zdde->zdde_ref_blocks;
		dds->dds_ref_lsize += zdde->zdde_ref_lsize;
		dds->dds_ref_psize += zdde->zdde_ref_psize;
		dds->dds_ref_dsize += zdde->zdde_ref_dsize;

		umem_free(zdde, sizeof (*zdde));
	}

	avl_destroy(&t);

	ddt_histogram_total(&dds_total, &ddh_total);

	(void) printf("Simulated DDT histogram:\n");

	zpool_dump_ddt(&dds_total, &ddh_total);

	dump_dedup_ratio(&dds_total);
}

static int
verify_device_removal_feature_counts(spa_t *spa)
{
	uint64_t dr_feature_refcount = 0;
	uint64_t oc_feature_refcount = 0;
	uint64_t indirect_vdev_count = 0;
	uint64_t precise_vdev_count = 0;
	uint64_t obsolete_counts_object_count = 0;
	uint64_t obsolete_sm_count = 0;
	uint64_t obsolete_counts_count = 0;
	uint64_t scip_count = 0;
	uint64_t obsolete_bpobj_count = 0;
	int ret = 0;

	spa_condensing_indirect_phys_t *scip =
	    &spa->spa_condensing_indirect_phys;
	if (scip->scip_next_mapping_object != 0) {
		vdev_t *vd = spa->spa_root_vdev->vdev_child[scip->scip_vdev];
		ASSERT(scip->scip_prev_obsolete_sm_object != 0);
		ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);

		(void) printf("Condensing indirect vdev %llu: new mapping "
		    "object %llu, prev obsolete sm %llu\n",
		    (u_longlong_t)scip->scip_vdev,
		    (u_longlong_t)scip->scip_next_mapping_object,
		    (u_longlong_t)scip->scip_prev_obsolete_sm_object);
		if (scip->scip_prev_obsolete_sm_object != 0) {
			space_map_t *prev_obsolete_sm = NULL;
			VERIFY0(space_map_open(&prev_obsolete_sm,
			    spa->spa_meta_objset,
			    scip->scip_prev_obsolete_sm_object,
			    0, vd->vdev_asize, 0));
			dump_spacemap(spa->spa_meta_objset, prev_obsolete_sm);
			(void) printf("\n");
			space_map_close(prev_obsolete_sm);
		}

		scip_count += 2;
	}

	for (uint64_t i = 0; i < spa->spa_root_vdev->vdev_children; i++) {
		vdev_t *vd = spa->spa_root_vdev->vdev_child[i];
		vdev_indirect_config_t *vic = &vd->vdev_indirect_config;

		if (vic->vic_mapping_object != 0) {
			ASSERT(vd->vdev_ops == &vdev_indirect_ops ||
			    vd->vdev_removing);
			indirect_vdev_count++;

			if (vd->vdev_indirect_mapping->vim_havecounts) {
				obsolete_counts_count++;
			}
		}

		boolean_t are_precise;
		VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise));
		if (are_precise) {
			ASSERT(vic->vic_mapping_object != 0);
			precise_vdev_count++;
		}

		uint64_t obsolete_sm_object;
		VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
		if (obsolete_sm_object != 0) {
			ASSERT(vic->vic_mapping_object != 0);
			obsolete_sm_count++;
		}
	}

	(void) feature_get_refcount(spa,
	    &spa_feature_table[SPA_FEATURE_DEVICE_REMOVAL],
	    &dr_feature_refcount);
	(void) feature_get_refcount(spa,
	    &spa_feature_table[SPA_FEATURE_OBSOLETE_COUNTS],
	    &oc_feature_refcount);

	if (dr_feature_refcount != indirect_vdev_count) {
		ret = 1;
		(void) printf("Number of indirect vdevs (%llu) " \
		    "does not match feature count (%llu)\n",
		    (u_longlong_t)indirect_vdev_count,
		    (u_longlong_t)dr_feature_refcount);
	} else {
		(void) printf("Verified device_removal feature refcount " \
		    "of %llu is correct\n",
		    (u_longlong_t)dr_feature_refcount);
	}

	if (zap_contains(spa_meta_objset(spa), DMU_POOL_DIRECTORY_OBJECT,
	    DMU_POOL_OBSOLETE_BPOBJ) == 0) {
		obsolete_bpobj_count++;
	}


	obsolete_counts_object_count = precise_vdev_count;
	obsolete_counts_object_count += obsolete_sm_count;
	obsolete_counts_object_count += obsolete_counts_count;
	obsolete_counts_object_count += scip_count;
	obsolete_counts_object_count += obsolete_bpobj_count;
	obsolete_counts_object_count += remap_deadlist_count;

	if (oc_feature_refcount != obsolete_counts_object_count) {
		ret = 1;
		(void) printf("Number of obsolete counts objects (%llu) " \
		    "does not match feature count (%llu)\n",
		    (u_longlong_t)obsolete_counts_object_count,
		    (u_longlong_t)oc_feature_refcount);
		(void) printf("pv:%llu os:%llu oc:%llu sc:%llu "
		    "ob:%llu rd:%llu\n",
		    (u_longlong_t)precise_vdev_count,
		    (u_longlong_t)obsolete_sm_count,
		    (u_longlong_t)obsolete_counts_count,
		    (u_longlong_t)scip_count,
		    (u_longlong_t)obsolete_bpobj_count,
		    (u_longlong_t)remap_deadlist_count);
	} else {
		(void) printf("Verified indirect_refcount feature refcount " \
		    "of %llu is correct\n",
		    (u_longlong_t)oc_feature_refcount);
	}
	return (ret);
}

static void
zdb_set_skip_mmp(char *target)
{
	spa_t *spa;

	/*
	 * Disable the activity check to allow examination of
	 * active pools.
	 */
	mutex_enter(&spa_namespace_lock);
	if ((spa = spa_lookup(target)) != NULL) {
		spa->spa_import_flags |= ZFS_IMPORT_SKIP_MMP;
	}
	mutex_exit(&spa_namespace_lock);
}

#define	BOGUS_SUFFIX "_CHECKPOINTED_UNIVERSE"
/*
 * Import the checkpointed state of the pool specified by the target
 * parameter as readonly. The function also accepts a pool config
 * as an optional parameter, else it attempts to infer the config by
 * the name of the target pool.
 *
 * Note that the checkpointed state's pool name will be the name of
 * the original pool with the above suffix appended to it. In addition,
 * if the target is not a pool name (e.g. a path to a dataset) then
 * the new_path parameter is populated with the updated path to
 * reflect the fact that we are looking into the checkpointed state.
 *
 * The function returns a newly-allocated copy of the name of the
 * pool containing the checkpointed state. When this copy is no
 * longer needed it should be freed with free(3C). Same thing
 * applies to the new_path parameter if allocated.
 */
static char *
import_checkpointed_state(char *target, nvlist_t *cfg, boolean_t target_is_spa,
    char **new_path)
{
	int error = 0;
	char *poolname, *bogus_name = NULL;
	boolean_t freecfg = B_FALSE;

	/* If the target is not a pool, the extract the pool name */
	char *path_start = strchr(target, '/');
	if (target_is_spa || path_start == NULL) {
		poolname = target;
	} else {
		size_t poolname_len = path_start - target;
		poolname = strndup(target, poolname_len);
	}

	if (cfg == NULL) {
		zdb_set_skip_mmp(poolname);
		error = spa_get_stats(poolname, &cfg, NULL, 0);
		if (error != 0) {
			fatal("Tried to read config of pool \"%s\" but "
			    "spa_get_stats() failed with error %d\n",
			    poolname, error);
		}
		freecfg = B_TRUE;
	}

	if (asprintf(&bogus_name, "%s%s", poolname, BOGUS_SUFFIX) == -1) {
		if (target != poolname)
			free(poolname);
		return (NULL);
	}
	fnvlist_add_string(cfg, ZPOOL_CONFIG_POOL_NAME, bogus_name);

	error = spa_import(bogus_name, cfg, NULL,
	    ZFS_IMPORT_MISSING_LOG | ZFS_IMPORT_CHECKPOINT |
	    ZFS_IMPORT_SKIP_MMP);
	if (freecfg)
		nvlist_free(cfg);
	if (error != 0) {
		fatal("Tried to import pool \"%s\" but spa_import() failed "
		    "with error %d\n", bogus_name, error);
	}

	if (new_path != NULL && !target_is_spa) {
		if (asprintf(new_path, "%s%s", bogus_name,
		    path_start != NULL ? path_start : "") == -1) {
			free(bogus_name);
			if (!target_is_spa && path_start != NULL)
				free(poolname);
			return (NULL);
		}
	}

	if (target != poolname)
		free(poolname);

	return (bogus_name);
}

typedef struct verify_checkpoint_sm_entry_cb_arg {
	vdev_t *vcsec_vd;

	/* the following fields are only used for printing progress */
	uint64_t vcsec_entryid;
	uint64_t vcsec_num_entries;
} verify_checkpoint_sm_entry_cb_arg_t;

#define	ENTRIES_PER_PROGRESS_UPDATE 10000

static int
verify_checkpoint_sm_entry_cb(space_map_entry_t *sme, void *arg)
{
	verify_checkpoint_sm_entry_cb_arg_t *vcsec = arg;
	vdev_t *vd = vcsec->vcsec_vd;
	metaslab_t *ms = vd->vdev_ms[sme->sme_offset >> vd->vdev_ms_shift];
	uint64_t end = sme->sme_offset + sme->sme_run;

	ASSERT(sme->sme_type == SM_FREE);

	if ((vcsec->vcsec_entryid % ENTRIES_PER_PROGRESS_UPDATE) == 0) {
		(void) fprintf(stderr,
		    "\rverifying vdev %llu, space map entry %llu of %llu ...",
		    (longlong_t)vd->vdev_id,
		    (longlong_t)vcsec->vcsec_entryid,
		    (longlong_t)vcsec->vcsec_num_entries);
	}
	vcsec->vcsec_entryid++;

	/*
	 * See comment in checkpoint_sm_exclude_entry_cb()
	 */
	VERIFY3U(sme->sme_offset, >=, ms->ms_start);
	VERIFY3U(end, <=, ms->ms_start + ms->ms_size);

	/*
	 * The entries in the vdev_checkpoint_sm should be marked as
	 * allocated in the checkpointed state of the pool, therefore
	 * their respective ms_allocateable trees should not contain them.
	 */
	mutex_enter(&ms->ms_lock);
	zfs_range_tree_verify_not_present(ms->ms_allocatable,
	    sme->sme_offset, sme->sme_run);
	mutex_exit(&ms->ms_lock);

	return (0);
}

/*
 * Verify that all segments in the vdev_checkpoint_sm are allocated
 * according to the checkpoint's ms_sm (i.e. are not in the checkpoint's
 * ms_allocatable).
 *
 * Do so by comparing the checkpoint space maps (vdev_checkpoint_sm) of
 * each vdev in the current state of the pool to the metaslab space maps
 * (ms_sm) of the checkpointed state of the pool.
 *
 * Note that the function changes the state of the ms_allocatable
 * trees of the current spa_t. The entries of these ms_allocatable
 * trees are cleared out and then repopulated from with the free
 * entries of their respective ms_sm space maps.
 */
static void
verify_checkpoint_vdev_spacemaps(spa_t *checkpoint, spa_t *current)
{
	vdev_t *ckpoint_rvd = checkpoint->spa_root_vdev;
	vdev_t *current_rvd = current->spa_root_vdev;

	load_concrete_ms_allocatable_trees(checkpoint, SM_FREE);

	for (uint64_t c = 0; c < ckpoint_rvd->vdev_children; c++) {
		vdev_t *ckpoint_vd = ckpoint_rvd->vdev_child[c];
		vdev_t *current_vd = current_rvd->vdev_child[c];

		space_map_t *checkpoint_sm = NULL;
		uint64_t checkpoint_sm_obj;

		if (ckpoint_vd->vdev_ops == &vdev_indirect_ops) {
			/*
			 * Since we don't allow device removal in a pool
			 * that has a checkpoint, we expect that all removed
			 * vdevs were removed from the pool before the
			 * checkpoint.
			 */
			ASSERT3P(current_vd->vdev_ops, ==, &vdev_indirect_ops);
			continue;
		}

		/*
		 * If the checkpoint space map doesn't exist, then nothing
		 * here is checkpointed so there's nothing to verify.
		 */
		if (current_vd->vdev_top_zap == 0 ||
		    zap_contains(spa_meta_objset(current),
		    current_vd->vdev_top_zap,
		    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM) != 0)
			continue;

		VERIFY0(zap_lookup(spa_meta_objset(current),
		    current_vd->vdev_top_zap, VDEV_TOP_ZAP_POOL_CHECKPOINT_SM,
		    sizeof (uint64_t), 1, &checkpoint_sm_obj));

		VERIFY0(space_map_open(&checkpoint_sm, spa_meta_objset(current),
		    checkpoint_sm_obj, 0, current_vd->vdev_asize,
		    current_vd->vdev_ashift));

		verify_checkpoint_sm_entry_cb_arg_t vcsec;
		vcsec.vcsec_vd = ckpoint_vd;
		vcsec.vcsec_entryid = 0;
		vcsec.vcsec_num_entries =
		    space_map_length(checkpoint_sm) / sizeof (uint64_t);
		VERIFY0(space_map_iterate(checkpoint_sm,
		    space_map_length(checkpoint_sm),
		    verify_checkpoint_sm_entry_cb, &vcsec));
		if (dump_opt['m'] > 3)
			dump_spacemap(current->spa_meta_objset, checkpoint_sm);
		space_map_close(checkpoint_sm);
	}

	/*
	 * If we've added vdevs since we took the checkpoint, ensure
	 * that their checkpoint space maps are empty.
	 */
	if (ckpoint_rvd->vdev_children < current_rvd->vdev_children) {
		for (uint64_t c = ckpoint_rvd->vdev_children;
		    c < current_rvd->vdev_children; c++) {
			vdev_t *current_vd = current_rvd->vdev_child[c];
			VERIFY0P(current_vd->vdev_checkpoint_sm);
		}
	}

	/* for cleaner progress output */
	(void) fprintf(stderr, "\n");
}

/*
 * Verifies that all space that's allocated in the checkpoint is
 * still allocated in the current version, by checking that everything
 * in checkpoint's ms_allocatable (which is actually allocated, not
 * allocatable/free) is not present in current's ms_allocatable.
 *
 * Note that the function changes the state of the ms_allocatable
 * trees of both spas when called. The entries of all ms_allocatable
 * trees are cleared out and then repopulated from their respective
 * ms_sm space maps. In the checkpointed state we load the allocated
 * entries, and in the current state we load the free entries.
 */
static void
verify_checkpoint_ms_spacemaps(spa_t *checkpoint, spa_t *current)
{
	vdev_t *ckpoint_rvd = checkpoint->spa_root_vdev;
	vdev_t *current_rvd = current->spa_root_vdev;

	load_concrete_ms_allocatable_trees(checkpoint, SM_ALLOC);
	load_concrete_ms_allocatable_trees(current, SM_FREE);

	for (uint64_t i = 0; i < ckpoint_rvd->vdev_children; i++) {
		vdev_t *ckpoint_vd = ckpoint_rvd->vdev_child[i];
		vdev_t *current_vd = current_rvd->vdev_child[i];

		if (ckpoint_vd->vdev_ops == &vdev_indirect_ops) {
			/*
			 * See comment in verify_checkpoint_vdev_spacemaps()
			 */
			ASSERT3P(current_vd->vdev_ops, ==, &vdev_indirect_ops);
			continue;
		}

		for (uint64_t m = 0; m < ckpoint_vd->vdev_ms_count; m++) {
			metaslab_t *ckpoint_msp = ckpoint_vd->vdev_ms[m];
			metaslab_t *current_msp = current_vd->vdev_ms[m];

			(void) fprintf(stderr,
			    "\rverifying vdev %llu of %llu, "
			    "metaslab %llu of %llu ...",
			    (longlong_t)current_vd->vdev_id,
			    (longlong_t)current_rvd->vdev_children,
			    (longlong_t)current_vd->vdev_ms[m]->ms_id,
			    (longlong_t)current_vd->vdev_ms_count);

			/*
			 * We walk through the ms_allocatable trees that
			 * are loaded with the allocated blocks from the
			 * ms_sm spacemaps of the checkpoint. For each
			 * one of these ranges we ensure that none of them
			 * exists in the ms_allocatable trees of the
			 * current state which are loaded with the ranges
			 * that are currently free.
			 *
			 * This way we ensure that none of the blocks that
			 * are part of the checkpoint were freed by mistake.
			 */
			zfs_range_tree_walk(ckpoint_msp->ms_allocatable,
			    (zfs_range_tree_func_t *)
			    zfs_range_tree_verify_not_present,
			    current_msp->ms_allocatable);
		}
	}

	/* for cleaner progress output */
	(void) fprintf(stderr, "\n");
}

static void
verify_checkpoint_blocks(spa_t *spa)
{
	ASSERT(!dump_opt['L']);

	spa_t *checkpoint_spa;
	char *checkpoint_pool;
	int error = 0;

	/*
	 * We import the checkpointed state of the pool (under a different
	 * name) so we can do verification on it against the current state
	 * of the pool.
	 */
	checkpoint_pool = import_checkpointed_state(spa->spa_name, NULL, B_TRUE,
	    NULL);
	ASSERT(strcmp(spa->spa_name, checkpoint_pool) != 0);

	error = spa_open(checkpoint_pool, &checkpoint_spa, FTAG);
	if (error != 0) {
		fatal("Tried to open pool \"%s\" but spa_open() failed with "
		    "error %d\n", checkpoint_pool, error);
	}

	/*
	 * Ensure that ranges in the checkpoint space maps of each vdev
	 * are allocated according to the checkpointed state's metaslab
	 * space maps.
	 */
	verify_checkpoint_vdev_spacemaps(checkpoint_spa, spa);

	/*
	 * Ensure that allocated ranges in the checkpoint's metaslab
	 * space maps remain allocated in the metaslab space maps of
	 * the current state.
	 */
	verify_checkpoint_ms_spacemaps(checkpoint_spa, spa);

	/*
	 * Once we are done, we get rid of the checkpointed state.
	 */
	spa_close(checkpoint_spa, FTAG);
	free(checkpoint_pool);
}

static void
dump_leftover_checkpoint_blocks(spa_t *spa)
{
	vdev_t *rvd = spa->spa_root_vdev;

	for (uint64_t i = 0; i < rvd->vdev_children; i++) {
		vdev_t *vd = rvd->vdev_child[i];

		space_map_t *checkpoint_sm = NULL;
		uint64_t checkpoint_sm_obj;

		if (vd->vdev_top_zap == 0)
			continue;

		if (zap_contains(spa_meta_objset(spa), vd->vdev_top_zap,
		    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM) != 0)
			continue;

		VERIFY0(zap_lookup(spa_meta_objset(spa), vd->vdev_top_zap,
		    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM,
		    sizeof (uint64_t), 1, &checkpoint_sm_obj));

		VERIFY0(space_map_open(&checkpoint_sm, spa_meta_objset(spa),
		    checkpoint_sm_obj, 0, vd->vdev_asize, vd->vdev_ashift));
		dump_spacemap(spa->spa_meta_objset, checkpoint_sm);
		space_map_close(checkpoint_sm);
	}
}

static int
verify_checkpoint(spa_t *spa)
{
	uberblock_t checkpoint;
	int error;

	if (!spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT))
		return (0);

	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
	    DMU_POOL_ZPOOL_CHECKPOINT, sizeof (uint64_t),
	    sizeof (uberblock_t) / sizeof (uint64_t), &checkpoint);

	if (error == ENOENT && !dump_opt['L']) {
		/*
		 * If the feature is active but the uberblock is missing
		 * then we must be in the middle of discarding the
		 * checkpoint.
		 */
		(void) printf("\nPartially discarded checkpoint "
		    "state found:\n");
		if (dump_opt['m'] > 3)
			dump_leftover_checkpoint_blocks(spa);
		return (0);
	} else if (error != 0) {
		(void) printf("lookup error %d when looking for "
		    "checkpointed uberblock in MOS\n", error);
		return (error);
	}
	dump_uberblock(&checkpoint, "\nCheckpointed uberblock found:\n", "\n");

	if (checkpoint.ub_checkpoint_txg == 0) {
		(void) printf("\nub_checkpoint_txg not set in checkpointed "
		    "uberblock\n");
		error = 3;
	}

	if (error == 0 && !dump_opt['L'])
		verify_checkpoint_blocks(spa);

	return (error);
}

static void
mos_leaks_cb(void *arg, uint64_t start, uint64_t size)
{
	(void) arg;
	for (uint64_t i = start; i < size; i++) {
		(void) printf("MOS object %llu referenced but not allocated\n",
		    (u_longlong_t)i);
	}
}

static void
mos_obj_refd(uint64_t obj)
{
	if (obj != 0 && mos_refd_objs != NULL)
		zfs_range_tree_add(mos_refd_objs, obj, 1);
}

/*
 * Call on a MOS object that may already have been referenced.
 */
static void
mos_obj_refd_multiple(uint64_t obj)
{
	if (obj != 0 && mos_refd_objs != NULL &&
	    !zfs_range_tree_contains(mos_refd_objs, obj, 1))
		zfs_range_tree_add(mos_refd_objs, obj, 1);
}

static void
mos_leak_vdev_top_zap(vdev_t *vd)
{
	uint64_t ms_flush_data_obj;
	int error = zap_lookup(spa_meta_objset(vd->vdev_spa),
	    vd->vdev_top_zap, VDEV_TOP_ZAP_MS_UNFLUSHED_PHYS_TXGS,
	    sizeof (ms_flush_data_obj), 1, &ms_flush_data_obj);
	if (error == ENOENT)
		return;
	ASSERT0(error);

	mos_obj_refd(ms_flush_data_obj);
}

static void
mos_leak_vdev(vdev_t *vd)
{
	mos_obj_refd(vd->vdev_dtl_object);
	mos_obj_refd(vd->vdev_ms_array);
	mos_obj_refd(vd->vdev_indirect_config.vic_births_object);
	mos_obj_refd(vd->vdev_indirect_config.vic_mapping_object);
	mos_obj_refd(vd->vdev_leaf_zap);
	if (vd->vdev_checkpoint_sm != NULL)
		mos_obj_refd(vd->vdev_checkpoint_sm->sm_object);
	if (vd->vdev_indirect_mapping != NULL) {
		mos_obj_refd(vd->vdev_indirect_mapping->
		    vim_phys->vimp_counts_object);
	}
	if (vd->vdev_obsolete_sm != NULL)
		mos_obj_refd(vd->vdev_obsolete_sm->sm_object);

	for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {
		metaslab_t *ms = vd->vdev_ms[m];
		mos_obj_refd(space_map_object(ms->ms_sm));
	}

	if (vd->vdev_root_zap != 0)
		mos_obj_refd(vd->vdev_root_zap);

	if (vd->vdev_top_zap != 0) {
		mos_obj_refd(vd->vdev_top_zap);
		mos_leak_vdev_top_zap(vd);
	}

	for (uint64_t c = 0; c < vd->vdev_children; c++) {
		mos_leak_vdev(vd->vdev_child[c]);
	}
}

static void
mos_leak_log_spacemaps(spa_t *spa)
{
	uint64_t spacemap_zap;
	int error = zap_lookup(spa_meta_objset(spa),
	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_LOG_SPACEMAP_ZAP,
	    sizeof (spacemap_zap), 1, &spacemap_zap);
	if (error == ENOENT)
		return;
	ASSERT0(error);

	mos_obj_refd(spacemap_zap);
	for (spa_log_sm_t *sls = avl_first(&spa->spa_sm_logs_by_txg);
	    sls; sls = AVL_NEXT(&spa->spa_sm_logs_by_txg, sls))
		mos_obj_refd(sls->sls_sm_obj);
}

static void
errorlog_count_refd(objset_t *mos, uint64_t errlog)
{
	zap_cursor_t zc;
	zap_attribute_t *za = zap_attribute_alloc();
	for (zap_cursor_init(&zc, mos, errlog);
	    zap_cursor_retrieve(&zc, za) == 0;
	    zap_cursor_advance(&zc)) {
		mos_obj_refd(za->za_first_integer);
	}
	zap_cursor_fini(&zc);
	zap_attribute_free(za);
}

static int
dump_mos_leaks(spa_t *spa)
{
	int rv = 0;
	objset_t *mos = spa->spa_meta_objset;
	dsl_pool_t *dp = spa->spa_dsl_pool;

	/* Visit and mark all referenced objects in the MOS */

	mos_obj_refd(DMU_POOL_DIRECTORY_OBJECT);
	mos_obj_refd(spa->spa_pool_props_object);
	mos_obj_refd(spa->spa_config_object);
	mos_obj_refd(spa->spa_ddt_stat_object);
	mos_obj_refd(spa->spa_feat_desc_obj);
	mos_obj_refd(spa->spa_feat_enabled_txg_obj);
	mos_obj_refd(spa->spa_feat_for_read_obj);
	mos_obj_refd(spa->spa_feat_for_write_obj);
	mos_obj_refd(spa->spa_history);
	mos_obj_refd(spa->spa_errlog_last);
	mos_obj_refd(spa->spa_errlog_scrub);

	if (spa_feature_is_enabled(spa, SPA_FEATURE_HEAD_ERRLOG)) {
		errorlog_count_refd(mos, spa->spa_errlog_last);
		errorlog_count_refd(mos, spa->spa_errlog_scrub);
	}

	mos_obj_refd(spa->spa_all_vdev_zaps);
	mos_obj_refd(spa->spa_dsl_pool->dp_bptree_obj);
	mos_obj_refd(spa->spa_dsl_pool->dp_tmp_userrefs_obj);
	mos_obj_refd(spa->spa_dsl_pool->dp_scan->scn_phys.scn_queue_obj);
	bpobj_count_refd(&spa->spa_deferred_bpobj);
	mos_obj_refd(dp->dp_empty_bpobj);
	bpobj_count_refd(&dp->dp_obsolete_bpobj);
	bpobj_count_refd(&dp->dp_free_bpobj);
	mos_obj_refd(spa->spa_l2cache.sav_object);
	mos_obj_refd(spa->spa_spares.sav_object);

	if (spa->spa_syncing_log_sm != NULL)
		mos_obj_refd(spa->spa_syncing_log_sm->sm_object);
	mos_leak_log_spacemaps(spa);

	mos_obj_refd(spa->spa_condensing_indirect_phys.
	    scip_next_mapping_object);
	mos_obj_refd(spa->spa_condensing_indirect_phys.
	    scip_prev_obsolete_sm_object);
	if (spa->spa_condensing_indirect_phys.scip_next_mapping_object != 0) {
		vdev_indirect_mapping_t *vim =
		    vdev_indirect_mapping_open(mos,
		    spa->spa_condensing_indirect_phys.scip_next_mapping_object);
		mos_obj_refd(vim->vim_phys->vimp_counts_object);
		vdev_indirect_mapping_close(vim);
	}
	deleted_livelists_dump_mos(spa);

	if (dp->dp_origin_snap != NULL) {
		dsl_dataset_t *ds;

		dsl_pool_config_enter(dp, FTAG);
		VERIFY0(dsl_dataset_hold_obj(dp,
		    dsl_dataset_phys(dp->dp_origin_snap)->ds_next_snap_obj,
		    FTAG, &ds));
		count_ds_mos_objects(ds);
		dump_blkptr_list(&ds->ds_deadlist, "Deadlist");
		dsl_dataset_rele(ds, FTAG);
		dsl_pool_config_exit(dp, FTAG);

		count_ds_mos_objects(dp->dp_origin_snap);
		dump_blkptr_list(&dp->dp_origin_snap->ds_deadlist, "Deadlist");
	}
	count_dir_mos_objects(dp->dp_mos_dir);
	if (dp->dp_free_dir != NULL)
		count_dir_mos_objects(dp->dp_free_dir);
	if (dp->dp_leak_dir != NULL)
		count_dir_mos_objects(dp->dp_leak_dir);

	mos_leak_vdev(spa->spa_root_vdev);

	for (uint64_t c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
		ddt_t *ddt = spa->spa_ddt[c];
		if (!ddt || ddt->ddt_version == DDT_VERSION_UNCONFIGURED)
			continue;

		/* DDT store objects */
		for (ddt_type_t type = 0; type < DDT_TYPES; type++) {
			for (ddt_class_t class = 0; class < DDT_CLASSES;
			    class++) {
				mos_obj_refd(ddt->ddt_object[type][class]);
			}
		}

		/* FDT container */
		if (ddt->ddt_version == DDT_VERSION_FDT)
			mos_obj_refd(ddt->ddt_dir_object);

		/* FDT log objects */
		if (ddt->ddt_flags & DDT_FLAG_LOG) {
			mos_obj_refd(ddt->ddt_log[0].ddl_object);
			mos_obj_refd(ddt->ddt_log[1].ddl_object);
		}
	}

	for (uint64_t vdevid = 0; vdevid < spa->spa_brt_nvdevs; vdevid++) {
		brt_vdev_t *brtvd = spa->spa_brt_vdevs[vdevid];
		if (brtvd->bv_initiated) {
			mos_obj_refd(brtvd->bv_mos_brtvdev);
			mos_obj_refd(brtvd->bv_mos_entries);
		}
	}

	/*
	 * Visit all allocated objects and make sure they are referenced.
	 */
	uint64_t object = 0;
	while (dmu_object_next(mos, &object, B_FALSE, 0) == 0) {
		if (zfs_range_tree_contains(mos_refd_objs, object, 1)) {
			zfs_range_tree_remove(mos_refd_objs, object, 1);
		} else {
			dmu_object_info_t doi;
			const char *name;
			VERIFY0(dmu_object_info(mos, object, &doi));
			if (doi.doi_type & DMU_OT_NEWTYPE) {
				dmu_object_byteswap_t bswap =
				    DMU_OT_BYTESWAP(doi.doi_type);
				name = dmu_ot_byteswap[bswap].ob_name;
			} else {
				name = dmu_ot[doi.doi_type].ot_name;
			}

			(void) printf("MOS object %llu (%s) leaked\n",
			    (u_longlong_t)object, name);
			rv = 2;
		}
	}
	(void) zfs_range_tree_walk(mos_refd_objs, mos_leaks_cb, NULL);
	if (!zfs_range_tree_is_empty(mos_refd_objs))
		rv = 2;
	zfs_range_tree_vacate(mos_refd_objs, NULL, NULL);
	zfs_range_tree_destroy(mos_refd_objs);
	return (rv);
}

typedef struct log_sm_obsolete_stats_arg {
	uint64_t lsos_current_txg;

	uint64_t lsos_total_entries;
	uint64_t lsos_valid_entries;

	uint64_t lsos_sm_entries;
	uint64_t lsos_valid_sm_entries;
} log_sm_obsolete_stats_arg_t;

static int
log_spacemap_obsolete_stats_cb(spa_t *spa, space_map_entry_t *sme,
    uint64_t txg, void *arg)
{
	log_sm_obsolete_stats_arg_t *lsos = arg;

	uint64_t offset = sme->sme_offset;
	uint64_t vdev_id = sme->sme_vdev;

	if (lsos->lsos_current_txg == 0) {
		/* this is the first log */
		lsos->lsos_current_txg = txg;
	} else if (lsos->lsos_current_txg < txg) {
		/* we just changed log - print stats and reset */
		(void) printf("%-8llu valid entries out of %-8llu - txg %llu\n",
		    (u_longlong_t)lsos->lsos_valid_sm_entries,
		    (u_longlong_t)lsos->lsos_sm_entries,
		    (u_longlong_t)lsos->lsos_current_txg);
		lsos->lsos_valid_sm_entries = 0;
		lsos->lsos_sm_entries = 0;
		lsos->lsos_current_txg = txg;
	}
	ASSERT3U(lsos->lsos_current_txg, ==, txg);

	lsos->lsos_sm_entries++;
	lsos->lsos_total_entries++;

	vdev_t *vd = vdev_lookup_top(spa, vdev_id);
	if (!vdev_is_concrete(vd))
		return (0);

	metaslab_t *ms = vd->vdev_ms[offset >> vd->vdev_ms_shift];
	ASSERT(sme->sme_type == SM_ALLOC || sme->sme_type == SM_FREE);

	if (txg < metaslab_unflushed_txg(ms))
		return (0);
	lsos->lsos_valid_sm_entries++;
	lsos->lsos_valid_entries++;
	return (0);
}

static void
dump_log_spacemap_obsolete_stats(spa_t *spa)
{
	if (!spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))
		return;

	log_sm_obsolete_stats_arg_t lsos = {0};

	(void) printf("Log Space Map Obsolete Entry Statistics:\n");

	iterate_through_spacemap_logs(spa,
	    log_spacemap_obsolete_stats_cb, &lsos);

	/* print stats for latest log */
	(void) printf("%-8llu valid entries out of %-8llu - txg %llu\n",
	    (u_longlong_t)lsos.lsos_valid_sm_entries,
	    (u_longlong_t)lsos.lsos_sm_entries,
	    (u_longlong_t)lsos.lsos_current_txg);

	(void) printf("%-8llu valid entries out of %-8llu - total\n\n",
	    (u_longlong_t)lsos.lsos_valid_entries,
	    (u_longlong_t)lsos.lsos_total_entries);
}

static void
dump_zpool(spa_t *spa)
{
	dsl_pool_t *dp = spa_get_dsl(spa);
	int rc = 0;

	if (dump_opt['y']) {
		livelist_metaslab_validate(spa);
	}

	if (dump_opt['S']) {
		dump_simulated_ddt(spa);
		return;
	}

	if (!dump_opt['e'] && dump_opt['C'] > 1) {
		(void) printf("\nCached configuration:\n");
		dump_nvlist(spa->spa_config, 8);
	}

	if (dump_opt['C'])
		dump_config(spa);

	if (dump_opt['u'])
		dump_uberblock(&spa->spa_uberblock, "\nUberblock:\n", "\n");

	if (dump_opt['D'])
		dump_all_ddts(spa);

	if (dump_opt['T'])
		dump_brt(spa);

	if (dump_opt['d'] > 2 || dump_opt['m'])
		dump_metaslabs(spa);
	if (dump_opt['M'])
		dump_metaslab_groups(spa, dump_opt['M'] > 1);
	if (dump_opt['d'] > 2 || dump_opt['m']) {
		dump_log_spacemaps(spa);
		dump_log_spacemap_obsolete_stats(spa);
	}

	if (dump_opt['d'] || dump_opt['i']) {
		spa_feature_t f;
		mos_refd_objs = zfs_range_tree_create_flags(
		    NULL, ZFS_RANGE_SEG64, NULL, 0, 0,
		    0, "dump_zpool:mos_refd_objs");
		dump_objset(dp->dp_meta_objset);

		if (dump_opt['d'] >= 3) {
			dsl_pool_t *dp = spa->spa_dsl_pool;
			dump_full_bpobj(&spa->spa_deferred_bpobj,
			    "Deferred frees", 0);
			if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
				dump_full_bpobj(&dp->dp_free_bpobj,
				    "Pool snapshot frees", 0);
			}
			if (bpobj_is_open(&dp->dp_obsolete_bpobj)) {
				ASSERT(spa_feature_is_enabled(spa,
				    SPA_FEATURE_DEVICE_REMOVAL));
				dump_full_bpobj(&dp->dp_obsolete_bpobj,
				    "Pool obsolete blocks", 0);
			}

			if (spa_feature_is_active(spa,
			    SPA_FEATURE_ASYNC_DESTROY)) {
				dump_bptree(spa->spa_meta_objset,
				    dp->dp_bptree_obj,
				    "Pool dataset frees");
			}
			dump_dtl(spa->spa_root_vdev, 0);
		}

		for (spa_feature_t f = 0; f < SPA_FEATURES; f++)
			global_feature_count[f] = UINT64_MAX;
		global_feature_count[SPA_FEATURE_REDACTION_BOOKMARKS] = 0;
		global_feature_count[SPA_FEATURE_REDACTION_LIST_SPILL] = 0;
		global_feature_count[SPA_FEATURE_BOOKMARK_WRITTEN] = 0;
		global_feature_count[SPA_FEATURE_LIVELIST] = 0;

		(void) dmu_objset_find(spa_name(spa), dump_one_objset,
		    NULL, DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);

		if (rc == 0 && !dump_opt['L'])
			rc = dump_mos_leaks(spa);

		for (f = 0; f < SPA_FEATURES; f++) {
			uint64_t refcount;

			uint64_t *arr;
			if (!(spa_feature_table[f].fi_flags &
			    ZFEATURE_FLAG_PER_DATASET)) {
				if (global_feature_count[f] == UINT64_MAX)
					continue;
				if (!spa_feature_is_enabled(spa, f)) {
					ASSERT0(global_feature_count[f]);
					continue;
				}
				arr = global_feature_count;
			} else {
				if (!spa_feature_is_enabled(spa, f)) {
					ASSERT0(dataset_feature_count[f]);
					continue;
				}
				arr = dataset_feature_count;
			}
			if (feature_get_refcount(spa, &spa_feature_table[f],
			    &refcount) == ENOTSUP)
				continue;
			if (arr[f] != refcount) {
				(void) printf("%s feature refcount mismatch: "
				    "%lld consumers != %lld refcount\n",
				    spa_feature_table[f].fi_uname,
				    (longlong_t)arr[f], (longlong_t)refcount);
				rc = 2;
			} else {
				(void) printf("Verified %s feature refcount "
				    "of %llu is correct\n",
				    spa_feature_table[f].fi_uname,
				    (longlong_t)refcount);
			}
		}

		if (rc == 0)
			rc = verify_device_removal_feature_counts(spa);
	}

	if (rc == 0 && (dump_opt['b'] || dump_opt['c']))
		rc = dump_block_stats(spa);

	if (rc == 0)
		rc = verify_spacemap_refcounts(spa);

	if (dump_opt['s'])
		show_pool_stats(spa);

	if (dump_opt['h'])
		dump_history(spa);

	if (rc == 0)
		rc = verify_checkpoint(spa);

	if (rc != 0) {
		dump_debug_buffer();
		zdb_exit(rc);
	}
}

#define	ZDB_FLAG_CHECKSUM	0x0001
#define	ZDB_FLAG_DECOMPRESS	0x0002
#define	ZDB_FLAG_BSWAP		0x0004
#define	ZDB_FLAG_GBH		0x0008
#define	ZDB_FLAG_INDIRECT	0x0010
#define	ZDB_FLAG_RAW		0x0020
#define	ZDB_FLAG_PRINT_BLKPTR	0x0040
#define	ZDB_FLAG_VERBOSE	0x0080

static int flagbits[256];
static char flagbitstr[16];

static void
zdb_print_blkptr(const blkptr_t *bp, int flags)
{
	char blkbuf[BP_SPRINTF_LEN];

	if (flags & ZDB_FLAG_BSWAP)
		byteswap_uint64_array((void *)bp, sizeof (blkptr_t));

	snprintf_blkptr(blkbuf, sizeof (blkbuf), bp);
	(void) printf("%s\n", blkbuf);
}

static void
zdb_dump_indirect(blkptr_t *bp, int nbps, int flags)
{
	int i;

	for (i = 0; i < nbps; i++)
		zdb_print_blkptr(&bp[i], flags);
}

static void
zdb_dump_gbh(void *buf, uint64_t size, int flags)
{
	zdb_dump_indirect((blkptr_t *)buf, gbh_nblkptrs(size), flags);
}

static void
zdb_dump_block_raw(void *buf, uint64_t size, int flags)
{
	if (flags & ZDB_FLAG_BSWAP)
		byteswap_uint64_array(buf, size);
	VERIFY(write(fileno(stdout), buf, size) == size);
}

static void
zdb_dump_block(char *label, void *buf, uint64_t size, int flags)
{
	uint64_t *d = (uint64_t *)buf;
	unsigned nwords = size / sizeof (uint64_t);
	int do_bswap = !!(flags & ZDB_FLAG_BSWAP);
	unsigned i, j;
	const char *hdr;
	char *c;


	if (do_bswap)
		hdr = " 7 6 5 4 3 2 1 0   f e d c b a 9 8";
	else
		hdr = " 0 1 2 3 4 5 6 7   8 9 a b c d e f";

	(void) printf("\n%s\n%6s   %s  0123456789abcdef\n", label, "", hdr);

#ifdef _ZFS_LITTLE_ENDIAN
	/* correct the endianness */
	do_bswap = !do_bswap;
#endif
	for (i = 0; i < nwords; i += 2) {
		(void) printf("%06llx:  %016llx  %016llx  ",
		    (u_longlong_t)(i * sizeof (uint64_t)),
		    (u_longlong_t)(do_bswap ? BSWAP_64(d[i]) : d[i]),
		    (u_longlong_t)(do_bswap ? BSWAP_64(d[i + 1]) : d[i + 1]));

		c = (char *)&d[i];
		for (j = 0; j < 2 * sizeof (uint64_t); j++)
			(void) printf("%c", isprint(c[j]) ? c[j] : '.');
		(void) printf("\n");
	}
}

/*
 * There are two acceptable formats:
 *	leaf_name	  - For example: c1t0d0 or /tmp/ztest.0a
 *	child[.child]*    - For example: 0.1.1
 *
 * The second form can be used to specify arbitrary vdevs anywhere
 * in the hierarchy.  For example, in a pool with a mirror of
 * RAID-Zs, you can specify either RAID-Z vdev with 0.0 or 0.1 .
 */
static vdev_t *
zdb_vdev_lookup(vdev_t *vdev, const char *path)
{
	char *s, *p, *q;
	unsigned i;

	if (vdev == NULL)
		return (NULL);

	/* First, assume the x.x.x.x format */
	i = strtoul(path, &s, 10);
	if (s == path || (s && *s != '.' && *s != '\0'))
		goto name;
	if (i >= vdev->vdev_children)
		return (NULL);

	vdev = vdev->vdev_child[i];
	if (s && *s == '\0')
		return (vdev);
	return (zdb_vdev_lookup(vdev, s+1));

name:
	for (i = 0; i < vdev->vdev_children; i++) {
		vdev_t *vc = vdev->vdev_child[i];

		if (vc->vdev_path == NULL) {
			vc = zdb_vdev_lookup(vc, path);
			if (vc == NULL)
				continue;
			else
				return (vc);
		}

		p = strrchr(vc->vdev_path, '/');
		p = p ? p + 1 : vc->vdev_path;
		q = &vc->vdev_path[strlen(vc->vdev_path) - 2];

		if (strcmp(vc->vdev_path, path) == 0)
			return (vc);
		if (strcmp(p, path) == 0)
			return (vc);
		if (strcmp(q, "s0") == 0 && strncmp(p, path, q - p) == 0)
			return (vc);
	}

	return (NULL);
}

static int
name_from_objset_id(spa_t *spa, uint64_t objset_id, char *outstr)
{
	dsl_dataset_t *ds;

	dsl_pool_config_enter(spa->spa_dsl_pool, FTAG);
	int error = dsl_dataset_hold_obj(spa->spa_dsl_pool, objset_id,
	    NULL, &ds);
	if (error != 0) {
		(void) fprintf(stderr, "failed to hold objset %llu: %s\n",
		    (u_longlong_t)objset_id, strerror(error));
		dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
		return (error);
	}
	dsl_dataset_name(ds, outstr);
	dsl_dataset_rele(ds, NULL);
	dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
	return (0);
}

static boolean_t
zdb_parse_block_sizes(char *sizes, uint64_t *lsize, uint64_t *psize)
{
	char *s0, *s1, *tmp = NULL;

	if (sizes == NULL)
		return (B_FALSE);

	s0 = strtok_r(sizes, "/", &tmp);
	if (s0 == NULL)
		return (B_FALSE);
	s1 = strtok_r(NULL, "/", &tmp);
	*lsize = strtoull(s0, NULL, 16);
	*psize = s1 ? strtoull(s1, NULL, 16) : *lsize;
	return (*lsize >= *psize && *psize > 0);
}

#define	ZIO_COMPRESS_MASK(alg)	(1ULL << (ZIO_COMPRESS_##alg))

static boolean_t
try_decompress_block(abd_t *pabd, uint64_t lsize, uint64_t psize,
    int flags, int cfunc, void *lbuf, void *lbuf2)
{
	if (flags & ZDB_FLAG_VERBOSE) {
		(void) fprintf(stderr,
		    "Trying %05llx -> %05llx (%s)\n",
		    (u_longlong_t)psize,
		    (u_longlong_t)lsize,
		    zio_compress_table[cfunc].ci_name);
	}

	/*
	 * We set lbuf to all zeros and lbuf2 to all
	 * ones, then decompress to both buffers and
	 * compare their contents. This way we can
	 * know if decompression filled exactly to
	 * lsize or if it left some bytes unwritten.
	 */

	memset(lbuf, 0x00, lsize);
	memset(lbuf2, 0xff, lsize);

	abd_t labd, labd2;
	abd_get_from_buf_struct(&labd, lbuf, lsize);
	abd_get_from_buf_struct(&labd2, lbuf2, lsize);

	boolean_t ret = B_FALSE;
	if (zio_decompress_data(cfunc, pabd,
	    &labd, psize, lsize, NULL) == 0 &&
	    zio_decompress_data(cfunc, pabd,
	    &labd2, psize, lsize, NULL) == 0 &&
	    memcmp(lbuf, lbuf2, lsize) == 0)
		ret = B_TRUE;

	abd_free(&labd2);
	abd_free(&labd);

	return (ret);
}

static uint64_t
zdb_decompress_block(abd_t *pabd, void *buf, void *lbuf, uint64_t lsize,
    uint64_t psize, int flags)
{
	(void) buf;
	uint64_t orig_lsize = lsize;
	boolean_t tryzle = ((getenv("ZDB_NO_ZLE") == NULL));
	/*
	 * We don't know how the data was compressed, so just try
	 * every decompress function at every inflated blocksize.
	 */
	void *lbuf2 = umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL);
	int cfuncs[ZIO_COMPRESS_FUNCTIONS] = { 0 };
	int *cfuncp = cfuncs;
	uint64_t maxlsize = SPA_MAXBLOCKSIZE;
	uint64_t mask = ZIO_COMPRESS_MASK(ON) | ZIO_COMPRESS_MASK(OFF) |
	    ZIO_COMPRESS_MASK(INHERIT) | ZIO_COMPRESS_MASK(EMPTY) |
	    ZIO_COMPRESS_MASK(ZLE);
	*cfuncp++ = ZIO_COMPRESS_LZ4;
	*cfuncp++ = ZIO_COMPRESS_LZJB;
	mask |= ZIO_COMPRESS_MASK(LZ4) | ZIO_COMPRESS_MASK(LZJB);
	/*
	 * Every gzip level has the same decompressor, no need to
	 * run it 9 times per bruteforce attempt.
	 */
	mask |= ZIO_COMPRESS_MASK(GZIP_2) | ZIO_COMPRESS_MASK(GZIP_3);
	mask |= ZIO_COMPRESS_MASK(GZIP_4) | ZIO_COMPRESS_MASK(GZIP_5);
	mask |= ZIO_COMPRESS_MASK(GZIP_6) | ZIO_COMPRESS_MASK(GZIP_7);
	mask |= ZIO_COMPRESS_MASK(GZIP_8) | ZIO_COMPRESS_MASK(GZIP_9);
	for (int c = 0; c < ZIO_COMPRESS_FUNCTIONS; c++)
		if (((1ULL << c) & mask) == 0)
			*cfuncp++ = c;

	/*
	 * On the one hand, with SPA_MAXBLOCKSIZE at 16MB, this
	 * could take a while and we should let the user know
	 * we are not stuck.  On the other hand, printing progress
	 * info gets old after a while.  User can specify 'v' flag
	 * to see the progression.
	 */
	if (lsize == psize)
		lsize += SPA_MINBLOCKSIZE;
	else
		maxlsize = lsize;

	for (; lsize <= maxlsize; lsize += SPA_MINBLOCKSIZE) {
		for (cfuncp = cfuncs; *cfuncp; cfuncp++) {
			if (try_decompress_block(pabd, lsize, psize, flags,
			    *cfuncp, lbuf, lbuf2)) {
				tryzle = B_FALSE;
				break;
			}
		}
		if (*cfuncp != 0)
			break;
	}
	if (tryzle) {
		for (lsize = orig_lsize; lsize <= maxlsize;
		    lsize += SPA_MINBLOCKSIZE) {
			if (try_decompress_block(pabd, lsize, psize, flags,
			    ZIO_COMPRESS_ZLE, lbuf, lbuf2)) {
				*cfuncp = ZIO_COMPRESS_ZLE;
				break;
			}
		}
	}
	umem_free(lbuf2, SPA_MAXBLOCKSIZE);

	if (*cfuncp == ZIO_COMPRESS_ZLE) {
		printf("\nZLE decompression was selected. If you "
		    "suspect the results are wrong,\ntry avoiding ZLE "
		    "by setting and exporting ZDB_NO_ZLE=\"true\"\n");
	}

	return (lsize > maxlsize ? -1 : lsize);
}

/*
 * Read a block from a pool and print it out.  The syntax of the
 * block descriptor is:
 *
 *	pool:vdev_specifier:offset:[lsize/]psize[:flags]
 *
 *	pool           - The name of the pool you wish to read from
 *	vdev_specifier - Which vdev (see comment for zdb_vdev_lookup)
 *	offset         - offset, in hex, in bytes
 *	size           - Amount of data to read, in hex, in bytes
 *	flags          - A string of characters specifying options
 *		 b: Decode a blkptr at given offset within block
 *		 c: Calculate and display checksums
 *		 d: Decompress data before dumping
 *		 e: Byteswap data before dumping
 *		 g: Display data as a gang block header
 *		 i: Display as an indirect block
 *		 r: Dump raw data to stdout
 *		 v: Verbose
 *
 */
static void
zdb_read_block(char *thing, spa_t *spa)
{
	blkptr_t blk, *bp = &blk;
	dva_t *dva = bp->blk_dva;
	int flags = 0;
	uint64_t offset = 0, psize = 0, lsize = 0, blkptr_offset = 0;
	zio_t *zio;
	vdev_t *vd;
	abd_t *pabd;
	void *lbuf, *buf;
	char *s, *p, *dup, *flagstr, *sizes, *tmp = NULL;
	const char *vdev, *errmsg = NULL;
	int i, len, error;
	boolean_t borrowed = B_FALSE, found = B_FALSE;

	dup = strdup(thing);
	s = strtok_r(dup, ":", &tmp);
	vdev = s ?: "";
	s = strtok_r(NULL, ":", &tmp);
	offset = strtoull(s ? s : "", NULL, 16);
	sizes = strtok_r(NULL, ":", &tmp);
	s = strtok_r(NULL, ":", &tmp);
	flagstr = strdup(s ?: "");

	if (!zdb_parse_block_sizes(sizes, &lsize, &psize))
		errmsg = "invalid size(s)";
	if (!IS_P2ALIGNED(psize, DEV_BSIZE) || !IS_P2ALIGNED(lsize, DEV_BSIZE))
		errmsg = "size must be a multiple of sector size";
	if (!IS_P2ALIGNED(offset, DEV_BSIZE))
		errmsg = "offset must be a multiple of sector size";
	if (errmsg) {
		(void) printf("Invalid block specifier: %s  - %s\n",
		    thing, errmsg);
		goto done;
	}

	tmp = NULL;
	for (s = strtok_r(flagstr, ":", &tmp);
	    s != NULL;
	    s = strtok_r(NULL, ":", &tmp)) {
		len = strlen(flagstr);
		for (i = 0; i < len; i++) {
			int bit = flagbits[(uchar_t)flagstr[i]];

			if (bit == 0) {
				(void) printf("***Ignoring flag: %c\n",
				    (uchar_t)flagstr[i]);
				continue;
			}
			found = B_TRUE;
			flags |= bit;

			p = &flagstr[i + 1];
			if (*p != ':' && *p != '\0') {
				int j = 0, nextbit = flagbits[(uchar_t)*p];
				char *end, offstr[8] = { 0 };
				if ((bit == ZDB_FLAG_PRINT_BLKPTR) &&
				    (nextbit == 0)) {
					/* look ahead to isolate the offset */
					while (nextbit == 0 &&
					    strchr(flagbitstr, *p) == NULL) {
						offstr[j] = *p;
						j++;
						if (i + j > strlen(flagstr))
							break;
						p++;
						nextbit = flagbits[(uchar_t)*p];
					}
					blkptr_offset = strtoull(offstr, &end,
					    16);
					i += j;
				} else if (nextbit == 0) {
					(void) printf("***Ignoring flag arg:"
					    " '%c'\n", (uchar_t)*p);
				}
			}
		}
	}
	if (blkptr_offset % sizeof (blkptr_t)) {
		printf("Block pointer offset 0x%llx "
		    "must be divisible by 0x%x\n",
		    (longlong_t)blkptr_offset, (int)sizeof (blkptr_t));
		goto done;
	}
	if (found == B_FALSE && strlen(flagstr) > 0) {
		printf("Invalid flag arg: '%s'\n", flagstr);
		goto done;
	}

	vd = zdb_vdev_lookup(spa->spa_root_vdev, vdev);
	if (vd == NULL) {
		(void) printf("***Invalid vdev: %s\n", vdev);
		goto done;
	} else {
		if (vd->vdev_path)
			(void) fprintf(stderr, "Found vdev: %s\n",
			    vd->vdev_path);
		else
			(void) fprintf(stderr, "Found vdev type: %s\n",
			    vd->vdev_ops->vdev_op_type);
	}

	pabd = abd_alloc_for_io(SPA_MAXBLOCKSIZE, B_FALSE);
	lbuf = umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL);

	BP_ZERO(bp);

	DVA_SET_VDEV(&dva[0], vd->vdev_id);
	DVA_SET_OFFSET(&dva[0], offset);
	DVA_SET_GANG(&dva[0], 0);
	DVA_SET_ASIZE(&dva[0], vdev_psize_to_asize(vd, psize));

	BP_SET_BIRTH(bp, TXG_INITIAL, TXG_INITIAL);

	BP_SET_LSIZE(bp, lsize);
	BP_SET_PSIZE(bp, psize);
	BP_SET_COMPRESS(bp, ZIO_COMPRESS_OFF);
	BP_SET_CHECKSUM(bp, ZIO_CHECKSUM_OFF);
	BP_SET_TYPE(bp, DMU_OT_NONE);
	BP_SET_LEVEL(bp, 0);
	BP_SET_DEDUP(bp, 0);
	BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);

	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
	zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);

	if (vd == vd->vdev_top) {
		/*
		 * Treat this as a normal block read.
		 */
		zio_nowait(zio_read(zio, spa, bp, pabd, psize, NULL, NULL,
		    ZIO_PRIORITY_SYNC_READ,
		    ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW, NULL));
	} else {
		/*
		 * Treat this as a vdev child I/O.
		 */
		zio_nowait(zio_vdev_child_io(zio, bp, vd, offset, pabd,
		    psize, ZIO_TYPE_READ, ZIO_PRIORITY_SYNC_READ,
		    ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY |
		    ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW | ZIO_FLAG_OPTIONAL,
		    NULL, NULL));
	}

	error = zio_wait(zio);
	spa_config_exit(spa, SCL_STATE, FTAG);

	if (error) {
		(void) printf("Read of %s failed, error: %d\n", thing, error);
		goto out;
	}

	uint64_t orig_lsize = lsize;
	buf = lbuf;
	if (flags & ZDB_FLAG_DECOMPRESS) {
		lsize = zdb_decompress_block(pabd, buf, lbuf,
		    lsize, psize, flags);
		if (lsize == -1) {
			(void) printf("Decompress of %s failed\n", thing);
			goto out;
		}
	} else {
		buf = abd_borrow_buf_copy(pabd, lsize);
		borrowed = B_TRUE;
	}
	/*
	 * Try to detect invalid block pointer.  If invalid, try
	 * decompressing.
	 */
	if ((flags & ZDB_FLAG_PRINT_BLKPTR || flags & ZDB_FLAG_INDIRECT) &&
	    !(flags & ZDB_FLAG_DECOMPRESS)) {
		const blkptr_t *b = (const blkptr_t *)(void *)
		    ((uintptr_t)buf + (uintptr_t)blkptr_offset);
		if (zfs_blkptr_verify(spa, b,
		    BLK_CONFIG_NEEDED, BLK_VERIFY_ONLY)) {
			abd_return_buf_copy(pabd, buf, lsize);
			borrowed = B_FALSE;
			buf = lbuf;
			lsize = zdb_decompress_block(pabd, buf,
			    lbuf, lsize, psize, flags);
			b = (const blkptr_t *)(void *)
			    ((uintptr_t)buf + (uintptr_t)blkptr_offset);
			if (lsize == -1 || zfs_blkptr_verify(spa, b,
			    BLK_CONFIG_NEEDED, BLK_VERIFY_LOG)) {
				printf("invalid block pointer at this DVA\n");
				goto out;
			}
		}
	}

	if (flags & ZDB_FLAG_PRINT_BLKPTR)
		zdb_print_blkptr((blkptr_t *)(void *)
		    ((uintptr_t)buf + (uintptr_t)blkptr_offset), flags);
	else if (flags & ZDB_FLAG_RAW)
		zdb_dump_block_raw(buf, lsize, flags);
	else if (flags & ZDB_FLAG_INDIRECT)
		zdb_dump_indirect((blkptr_t *)buf,
		    orig_lsize / sizeof (blkptr_t), flags);
	else if (flags & ZDB_FLAG_GBH)
		zdb_dump_gbh(buf, lsize, flags);
	else
		zdb_dump_block(thing, buf, lsize, flags);

	/*
	 * If :c was specified, iterate through the checksum table to
	 * calculate and display each checksum for our specified
	 * DVA and length.
	 */
	if ((flags & ZDB_FLAG_CHECKSUM) && !(flags & ZDB_FLAG_RAW) &&
	    !(flags & ZDB_FLAG_GBH)) {
		zio_t *czio;
		(void) printf("\n");
		for (enum zio_checksum ck = ZIO_CHECKSUM_LABEL;
		    ck < ZIO_CHECKSUM_FUNCTIONS; ck++) {

			if ((zio_checksum_table[ck].ci_flags &
			    ZCHECKSUM_FLAG_EMBEDDED) ||
			    ck == ZIO_CHECKSUM_NOPARITY) {
				continue;
			}
			BP_SET_CHECKSUM(bp, ck);
			spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
			czio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
			if (vd == vd->vdev_top) {
				zio_nowait(zio_read(czio, spa, bp, pabd, psize,
				    NULL, NULL,
				    ZIO_PRIORITY_SYNC_READ,
				    ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW |
				    ZIO_FLAG_DONT_RETRY, NULL));
			} else {
				zio_nowait(zio_vdev_child_io(czio, bp, vd,
				    offset, pabd, psize, ZIO_TYPE_READ,
				    ZIO_PRIORITY_SYNC_READ,
				    ZIO_FLAG_DONT_PROPAGATE |
				    ZIO_FLAG_DONT_RETRY |
				    ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW |
				    ZIO_FLAG_SPECULATIVE |
				    ZIO_FLAG_OPTIONAL, NULL, NULL));
			}
			error = zio_wait(czio);
			if (error == 0 || error == ECKSUM) {
				zio_t *ck_zio = zio_null(NULL, spa, NULL,
				    NULL, NULL, 0);
				ck_zio->io_offset =
				    DVA_GET_OFFSET(&bp->blk_dva[0]);
				ck_zio->io_bp = bp;
				zio_checksum_compute(ck_zio, ck, pabd, psize);
				printf(
				    "%12s\t"
				    "cksum=%016llx:%016llx:%016llx:%016llx\n",
				    zio_checksum_table[ck].ci_name,
				    (u_longlong_t)bp->blk_cksum.zc_word[0],
				    (u_longlong_t)bp->blk_cksum.zc_word[1],
				    (u_longlong_t)bp->blk_cksum.zc_word[2],
				    (u_longlong_t)bp->blk_cksum.zc_word[3]);
				zio_wait(ck_zio);
			} else {
				printf("error %d reading block\n", error);
			}
			spa_config_exit(spa, SCL_STATE, FTAG);
		}
	}

	if (borrowed)
		abd_return_buf_copy(pabd, buf, lsize);

out:
	abd_free(pabd);
	umem_free(lbuf, SPA_MAXBLOCKSIZE);
done:
	free(flagstr);
	free(dup);
}

static void
zdb_embedded_block(char *thing)
{
	blkptr_t bp = {{{{0}}}};
	unsigned long long *words = (void *)&bp;
	char *buf;
	int err;

	err = sscanf(thing, "%llx:%llx:%llx:%llx:%llx:%llx:%llx:%llx:"
	    "%llx:%llx:%llx:%llx:%llx:%llx:%llx:%llx",
	    words + 0, words + 1, words + 2, words + 3,
	    words + 4, words + 5, words + 6, words + 7,
	    words + 8, words + 9, words + 10, words + 11,
	    words + 12, words + 13, words + 14, words + 15);
	if (err != 16) {
		(void) fprintf(stderr, "invalid input format\n");
		zdb_exit(1);
	}
	ASSERT3U(BPE_GET_LSIZE(&bp), <=, SPA_MAXBLOCKSIZE);
	buf = malloc(SPA_MAXBLOCKSIZE);
	if (buf == NULL) {
		(void) fprintf(stderr, "out of memory\n");
		zdb_exit(1);
	}
	err = decode_embedded_bp(&bp, buf, BPE_GET_LSIZE(&bp));
	if (err != 0) {
		(void) fprintf(stderr, "decode failed: %u\n", err);
		zdb_exit(1);
	}
	zdb_dump_block_raw(buf, BPE_GET_LSIZE(&bp), 0);
	free(buf);
}

/* check for valid hex or decimal numeric string */
static boolean_t
zdb_numeric(char *str)
{
	int i = 0, len;

	len = strlen(str);
	if (len == 0)
		return (B_FALSE);
	if (strncmp(str, "0x", 2) == 0 || strncmp(str, "0X", 2) == 0)
		i = 2;
	for (; i < len; i++) {
		if (!isxdigit(str[i]))
			return (B_FALSE);
	}
	return (B_TRUE);
}

static int
dummy_get_file_info(dmu_object_type_t bonustype, const void *data,
    zfs_file_info_t *zoi)
{
	(void) data, (void) zoi;

	if (bonustype != DMU_OT_ZNODE && bonustype != DMU_OT_SA)
		return (ENOENT);

	(void) fprintf(stderr, "dummy_get_file_info: not implemented");
	abort();
}

int
main(int argc, char **argv)
{
	int c;
	int dump_all = 1;
	int verbose = 0;
	int error = 0;
	char **searchdirs = NULL;
	int nsearch = 0;
	char *target, *target_pool, dsname[ZFS_MAX_DATASET_NAME_LEN];
	nvlist_t *policy = NULL;
	uint64_t max_txg = UINT64_MAX;
	int64_t objset_id = -1;
	uint64_t object;
	int flags = ZFS_IMPORT_MISSING_LOG;
	int rewind = ZPOOL_NEVER_REWIND;
	char *spa_config_path_env, *objset_str;
	boolean_t target_is_spa = B_TRUE, dataset_lookup = B_FALSE;
	nvlist_t *cfg = NULL;
	struct sigaction action;
	boolean_t force_import = B_FALSE;
	boolean_t config_path_console = B_FALSE;
	char pbuf[MAXPATHLEN];

	dprintf_setup(&argc, argv);

	/*
	 * Set up signal handlers, so if we crash due to bad on-disk data we
	 * can get more info. Unlike ztest, we don't bail out if we can't set
	 * up signal handlers, because zdb is very useful without them.
	 */
	action.sa_handler = sig_handler;
	sigemptyset(&action.sa_mask);
	action.sa_flags = 0;
	if (sigaction(SIGSEGV, &action, NULL) < 0) {
		(void) fprintf(stderr, "zdb: cannot catch SIGSEGV: %s\n",
		    strerror(errno));
	}
	if (sigaction(SIGABRT, &action, NULL) < 0) {
		(void) fprintf(stderr, "zdb: cannot catch SIGABRT: %s\n",
		    strerror(errno));
	}

	/*
	 * If there is an environment variable SPA_CONFIG_PATH it overrides
	 * default spa_config_path setting. If -U flag is specified it will
	 * override this environment variable settings once again.
	 */
	spa_config_path_env = getenv("SPA_CONFIG_PATH");
	if (spa_config_path_env != NULL)
		spa_config_path = spa_config_path_env;

	/*
	 * For performance reasons, we set this tunable down. We do so before
	 * the arg parsing section so that the user can override this value if
	 * they choose.
	 */
	zfs_btree_verify_intensity = 3;

	struct option long_options[] = {
		{"ignore-assertions",	no_argument,		NULL, 'A'},
		{"block-stats",		no_argument,		NULL, 'b'},
		{"backup",		no_argument,		NULL, 'B'},
		{"checksum",		no_argument,		NULL, 'c'},
		{"config",		no_argument,		NULL, 'C'},
		{"datasets",		no_argument,		NULL, 'd'},
		{"dedup-stats",		no_argument,		NULL, 'D'},
		{"exported",		no_argument,		NULL, 'e'},
		{"embedded-block-pointer",	no_argument,	NULL, 'E'},
		{"automatic-rewind",	no_argument,		NULL, 'F'},
		{"dump-debug-msg",	no_argument,		NULL, 'G'},
		{"history",		no_argument,		NULL, 'h'},
		{"intent-logs",		no_argument,		NULL, 'i'},
		{"inflight",		required_argument,	NULL, 'I'},
		{"checkpointed-state",	no_argument,		NULL, 'k'},
		{"key",			required_argument,	NULL, 'K'},
		{"label",		no_argument,		NULL, 'l'},
		{"disable-leak-tracking",	no_argument,	NULL, 'L'},
		{"metaslabs",		no_argument,		NULL, 'm'},
		{"metaslab-groups",	no_argument,		NULL, 'M'},
		{"numeric",		no_argument,		NULL, 'N'},
		{"option",		required_argument,	NULL, 'o'},
		{"object-lookups",	no_argument,		NULL, 'O'},
		{"path",		required_argument,	NULL, 'p'},
		{"parseable",		no_argument,		NULL, 'P'},
		{"skip-label",		no_argument,		NULL, 'q'},
		{"copy-object",		no_argument,		NULL, 'r'},
		{"read-block",		no_argument,		NULL, 'R'},
		{"io-stats",		no_argument,		NULL, 's'},
		{"simulate-dedup",	no_argument,		NULL, 'S'},
		{"txg",			required_argument,	NULL, 't'},
		{"brt-stats",		no_argument,		NULL, 'T'},
		{"uberblock",		no_argument,		NULL, 'u'},
		{"cachefile",		required_argument,	NULL, 'U'},
		{"verbose",		no_argument,		NULL, 'v'},
		{"verbatim",		no_argument,		NULL, 'V'},
		{"dump-blocks",		required_argument,	NULL, 'x'},
		{"extreme-rewind",	no_argument,		NULL, 'X'},
		{"all-reconstruction",	no_argument,		NULL, 'Y'},
		{"livelist",		no_argument,		NULL, 'y'},
		{"zstd-headers",	no_argument,		NULL, 'Z'},
		{"allocated-map",	no_argument,		NULL,
		    ALLOCATED_OPT},
		{0, 0, 0, 0}
	};

	while ((c = getopt_long(argc, argv,
	    "AbBcCdDeEFGhiI:kK:lLmMNo:Op:PqrRsSt:TuU:vVx:XYyZ",
	    long_options, NULL)) != -1) {
		switch (c) {
		case 'b':
		case 'B':
		case 'c':
		case 'C':
		case 'd':
		case 'D':
		case 'E':
		case 'G':
		case 'h':
		case 'i':
		case 'l':
		case 'm':
		case 'M':
		case 'N':
		case 'O':
		case 'r':
		case 'R':
		case 's':
		case 'S':
		case 'T':
		case 'u':
		case 'y':
		case 'Z':
		case ALLOCATED_OPT:
			dump_opt[c]++;
			dump_all = 0;
			break;
		case 'A':
		case 'e':
		case 'F':
		case 'k':
		case 'L':
		case 'P':
		case 'q':
		case 'X':
			dump_opt[c]++;
			break;
		case 'Y':
			zfs_reconstruct_indirect_combinations_max = INT_MAX;
			zfs_deadman_enabled = 0;
			break;
		/* NB: Sort single match options below. */
		case 'I':
			max_inflight_bytes = strtoull(optarg, NULL, 0);
			if (max_inflight_bytes == 0) {
				(void) fprintf(stderr, "maximum number "
				    "of inflight bytes must be greater "
				    "than 0\n");
				usage();
			}
			break;
		case 'K':
			dump_opt[c]++;
			key_material = strdup(optarg);
			/* redact key material in process table */
			while (*optarg != '\0') { *optarg++ = '*'; }
			break;
		case 'o':
			dump_opt[c]++;
			dump_all = 0;
			error = handle_tunable_option(optarg, B_FALSE);
			if (error != 0)
				zdb_exit(1);
			break;
		case 'p':
			if (searchdirs == NULL) {
				searchdirs = umem_alloc(sizeof (char *),
				    UMEM_NOFAIL);
			} else {
				char **tmp = umem_alloc((nsearch + 1) *
				    sizeof (char *), UMEM_NOFAIL);
				memcpy(tmp, searchdirs, nsearch *
				    sizeof (char *));
				umem_free(searchdirs,
				    nsearch * sizeof (char *));
				searchdirs = tmp;
			}
			searchdirs[nsearch++] = optarg;
			break;
		case 't':
			max_txg = strtoull(optarg, NULL, 0);
			if (max_txg < TXG_INITIAL) {
				(void) fprintf(stderr, "incorrect txg "
				    "specified: %s\n", optarg);
				usage();
			}
			break;
		case 'U':
			config_path_console = B_TRUE;
			spa_config_path = optarg;
			if (spa_config_path[0] != '/') {
				(void) fprintf(stderr,
				    "cachefile must be an absolute path "
				    "(i.e. start with a slash)\n");
				usage();
			}
			break;
		case 'v':
			verbose++;
			break;
		case 'V':
			flags = ZFS_IMPORT_VERBATIM;
			break;
		case 'x':
			vn_dumpdir = optarg;
			break;
		default:
			usage();
			break;
		}
	}

	if (!dump_opt['e'] && searchdirs != NULL) {
		(void) fprintf(stderr, "-p option requires use of -e\n");
		usage();
	}
#if defined(_LP64)
	/*
	 * ZDB does not typically re-read blocks; therefore limit the ARC
	 * to 256 MB, which can be used entirely for metadata.
	 */
	zfs_arc_min = 2ULL << SPA_MAXBLOCKSHIFT;
	zfs_arc_max = 256 * 1024 * 1024;
#endif

	/*
	 * "zdb -c" uses checksum-verifying scrub i/os which are async reads.
	 * "zdb -b" uses traversal prefetch which uses async reads.
	 * For good performance, let several of them be active at once.
	 */
	zfs_vdev_async_read_max_active = 10;

	/*
	 * Disable reference tracking for better performance.
	 */
	reference_tracking_enable = B_FALSE;

	/*
	 * Do not fail spa_load when spa_load_verify fails. This is needed
	 * to load non-idle pools.
	 */
	spa_load_verify_dryrun = B_TRUE;

	/*
	 * ZDB should have ability to read spacemaps.
	 */
	spa_mode_readable_spacemaps = B_TRUE;

	if (dump_all)
		verbose = MAX(verbose, 1);

	for (c = 0; c < 256; c++) {
		if (dump_all && strchr("ABeEFkKlLNOPrRSXy", c) == NULL)
			dump_opt[c] = 1;
		if (dump_opt[c])
			dump_opt[c] += verbose;
	}

	libspl_set_assert_ok((dump_opt['A'] == 1) || (dump_opt['A'] > 2));
	zfs_recover = (dump_opt['A'] > 1);

	argc -= optind;
	argv += optind;
	if (argc < 2 && dump_opt['R'])
		usage();

	target = argv[0];

	/*
	 * Automate cachefile
	 */
	if (!spa_config_path_env && !config_path_console && target &&
	    libzfs_core_init() == 0) {
		char *pname = strdup(target);
		const char *value;
		nvlist_t *pnvl = NULL;
		nvlist_t *vnvl = NULL;

		if (strpbrk(pname, "/@") != NULL)
			*strpbrk(pname, "/@") = '\0';

		if (pname && lzc_get_props(pname, &pnvl) == 0) {
			if (nvlist_lookup_nvlist(pnvl, "cachefile",
			    &vnvl) == 0) {
				value = fnvlist_lookup_string(vnvl,
				    ZPROP_VALUE);
			} else {
				value = "-";
			}
			strlcpy(pbuf, value, sizeof (pbuf));
			if (pbuf[0] != '\0') {
				if (pbuf[0] == '/') {
					if (access(pbuf, F_OK) == 0)
						spa_config_path = pbuf;
					else
						force_import = B_TRUE;
				} else if ((strcmp(pbuf, "-") == 0 &&
				    access(ZPOOL_CACHE, F_OK) != 0) ||
				    strcmp(pbuf, "none") == 0) {
					force_import = B_TRUE;
				}
			}
			nvlist_free(vnvl);
		}

		free(pname);
		nvlist_free(pnvl);
		libzfs_core_fini();
	}

	dmu_objset_register_type(DMU_OST_ZFS, dummy_get_file_info);
	kernel_init(SPA_MODE_READ);
	kernel_init_done = B_TRUE;

	if (dump_opt['E']) {
		if (argc != 1)
			usage();
		zdb_embedded_block(argv[0]);
		error = 0;
		goto fini;
	}

	if (argc < 1) {
		if (!dump_opt['e'] && dump_opt['C']) {
			dump_cachefile(spa_config_path);
			error = 0;
			goto fini;
		}
		if (dump_opt['o'])
			/*
			 * Avoid blasting tunable options off the top of the
			 * screen.
			 */
			zdb_exit(1);
		usage();
	}

	if (dump_opt['l']) {
		error = dump_label(argv[0]);
		goto fini;
	}

	if (dump_opt['X'] || dump_opt['F'])
		rewind = ZPOOL_DO_REWIND |
		    (dump_opt['X'] ? ZPOOL_EXTREME_REWIND : 0);

	/* -N implies -d */
	if (dump_opt['N'] && dump_opt['d'] == 0)
		dump_opt['d'] = dump_opt['N'];

	if (nvlist_alloc(&policy, NV_UNIQUE_NAME_TYPE, 0) != 0 ||
	    nvlist_add_uint64(policy, ZPOOL_LOAD_REQUEST_TXG, max_txg) != 0 ||
	    nvlist_add_uint32(policy, ZPOOL_LOAD_REWIND_POLICY, rewind) != 0)
		fatal("internal error: %s", strerror(ENOMEM));

	error = 0;

	if (strpbrk(target, "/@") != NULL) {
		size_t targetlen;

		target_pool = strdup(target);
		*strpbrk(target_pool, "/@") = '\0';

		target_is_spa = B_FALSE;
		targetlen = strlen(target);
		if (targetlen && target[targetlen - 1] == '/')
			target[targetlen - 1] = '\0';

		/*
		 * See if an objset ID was supplied (-d <pool>/<objset ID>).
		 * To disambiguate tank/100, consider the 100 as objsetID
		 * if -N was given, otherwise 100 is an objsetID iff
		 * tank/100 as a named dataset fails on lookup.
		 */
		objset_str = strchr(target, '/');
		if (objset_str && strlen(objset_str) > 1 &&
		    zdb_numeric(objset_str + 1)) {
			char *endptr;
			errno = 0;
			objset_str++;
			objset_id = strtoull(objset_str, &endptr, 0);
			/* dataset 0 is the same as opening the pool */
			if (errno == 0 && endptr != objset_str &&
			    objset_id != 0) {
				if (dump_opt['N'])
					dataset_lookup = B_TRUE;
			}
			/* normal dataset name not an objset ID */
			if (endptr == objset_str) {
				objset_id = -1;
			}
		} else if (objset_str && !zdb_numeric(objset_str + 1) &&
		    dump_opt['N']) {
			printf("Supply a numeric objset ID with -N\n");
			error = 2;
			goto fini;
		}
	} else {
		target_pool = target;
	}

	if (dump_opt['e'] || force_import) {
		importargs_t args = { 0 };

		/*
		 * If path is not provided, search in /dev
		 */
		if (searchdirs == NULL) {
			searchdirs = umem_alloc(sizeof (char *), UMEM_NOFAIL);
			searchdirs[nsearch++] = (char *)ZFS_DEVDIR;
		}

		args.paths = nsearch;
		args.path = searchdirs;
		args.can_be_active = B_TRUE;

		libpc_handle_t lpch = {
			.lpc_lib_handle = NULL,
			.lpc_ops = &libzpool_config_ops,
			.lpc_printerr = B_TRUE
		};
		error = zpool_find_config(&lpch, target_pool, &cfg, &args);

		if (error == 0) {

			if (nvlist_add_nvlist(cfg,
			    ZPOOL_LOAD_POLICY, policy) != 0) {
				fatal("can't open '%s': %s",
				    target, strerror(ENOMEM));
			}

			if (dump_opt['C'] > 1) {
				(void) printf("\nConfiguration for import:\n");
				dump_nvlist(cfg, 8);
			}

			/*
			 * Disable the activity check to allow examination of
			 * active pools.
			 */
			error = spa_import(target_pool, cfg, NULL,
			    flags | ZFS_IMPORT_SKIP_MMP);
		}
	}

	if (searchdirs != NULL) {
		umem_free(searchdirs, nsearch * sizeof (char *));
		searchdirs = NULL;
	}

	/*
	 * We need to make sure to process -O option or call
	 * dump_path after the -e option has been processed,
	 * which imports the pool to the namespace if it's
	 * not in the cachefile.
	 */
	if (dump_opt['O']) {
		if (argc != 2)
			usage();
		dump_opt['v'] = verbose + 3;
		error = dump_path(argv[0], argv[1], NULL);
		goto fini;
	}

	if (dump_opt['r']) {
		target_is_spa = B_FALSE;
		if (argc != 3)
			usage();
		dump_opt['v'] = verbose;
		error = dump_path(argv[0], argv[1], &object);
		if (error != 0)
			fatal("internal error: %s", strerror(error));
	}

	/*
	 * import_checkpointed_state makes the assumption that the
	 * target pool that we pass it is already part of the spa
	 * namespace. Because of that we need to make sure to call
	 * it always after the -e option has been processed, which
	 * imports the pool to the namespace if it's not in the
	 * cachefile.
	 */
	char *checkpoint_pool = NULL;
	char *checkpoint_target = NULL;
	if (dump_opt['k']) {
		checkpoint_pool = import_checkpointed_state(target, cfg,
		    target_is_spa, &checkpoint_target);

		if (checkpoint_target != NULL)
			target = checkpoint_target;
	}

	if (cfg != NULL) {
		nvlist_free(cfg);
		cfg = NULL;
	}

	if (target_pool != target)
		free(target_pool);

	if (error == 0) {
		if (dump_opt['k'] && (target_is_spa || dump_opt['R'])) {
			ASSERT(checkpoint_pool != NULL);
			ASSERT0P(checkpoint_target);

			error = spa_open(checkpoint_pool, &spa, FTAG);
			if (error != 0) {
				fatal("Tried to open pool \"%s\" but "
				    "spa_open() failed with error %d\n",
				    checkpoint_pool, error);
			}

		} else if (target_is_spa || dump_opt['R'] || dump_opt['B'] ||
		    objset_id == 0) {
			zdb_set_skip_mmp(target);
			error = spa_open_rewind(target, &spa, FTAG, policy,
			    NULL);
			if (error) {
				/*
				 * If we're missing the log device then
				 * try opening the pool after clearing the
				 * log state.
				 */
				mutex_enter(&spa_namespace_lock);
				if ((spa = spa_lookup(target)) != NULL &&
				    spa->spa_log_state == SPA_LOG_MISSING) {
					spa->spa_log_state = SPA_LOG_CLEAR;
					error = 0;
				}
				mutex_exit(&spa_namespace_lock);

				if (!error) {
					error = spa_open_rewind(target, &spa,
					    FTAG, policy, NULL);
				}
			}
		} else if (strpbrk(target, "#") != NULL) {
			dsl_pool_t *dp;
			error = dsl_pool_hold(target, FTAG, &dp);
			if (error != 0) {
				fatal("can't dump '%s': %s", target,
				    strerror(error));
			}
			error = dump_bookmark(dp, target, B_TRUE, verbose > 1);
			dsl_pool_rele(dp, FTAG);
			if (error != 0) {
				fatal("can't dump '%s': %s", target,
				    strerror(error));
			}
			goto fini;
		} else {
			target_pool = strdup(target);
			if (strpbrk(target, "/@") != NULL)
				*strpbrk(target_pool, "/@") = '\0';

			zdb_set_skip_mmp(target);
			/*
			 * If -N was supplied, the user has indicated that
			 * zdb -d <pool>/<objsetID> is in effect.  Otherwise
			 * we first assume that the dataset string is the
			 * dataset name.  If dmu_objset_hold fails with the
			 * dataset string, and we have an objset_id, retry the
			 * lookup with the objsetID.
			 */
			boolean_t retry = B_TRUE;
retry_lookup:
			if (dataset_lookup == B_TRUE) {
				/*
				 * Use the supplied id to get the name
				 * for open_objset.
				 */
				error = spa_open(target_pool, &spa, FTAG);
				if (error == 0) {
					error = name_from_objset_id(spa,
					    objset_id, dsname);
					spa_close(spa, FTAG);
					if (error == 0)
						target = dsname;
				}
			}
			if (error == 0) {
				if (objset_id > 0 && retry) {
					int err = dmu_objset_hold(target, FTAG,
					    &os);
					if (err) {
						dataset_lookup = B_TRUE;
						retry = B_FALSE;
						goto retry_lookup;
					} else {
						dmu_objset_rele(os, FTAG);
					}
				}
				error = open_objset(target, FTAG, &os);
			}
			if (error == 0)
				spa = dmu_objset_spa(os);
			free(target_pool);
		}
	}
	nvlist_free(policy);

	if (error)
		fatal("can't open '%s': %s", target, strerror(error));

	/*
	 * Set the pool failure mode to panic in order to prevent the pool
	 * from suspending.  A suspended I/O will have no way to resume and
	 * can prevent the zdb(8) command from terminating as expected.
	 */
	if (spa != NULL)
		spa->spa_failmode = ZIO_FAILURE_MODE_PANIC;

	argv++;
	argc--;
	if (dump_opt['r']) {
		error = zdb_copy_object(os, object, argv[1]);
	} else if (!dump_opt['R']) {
		flagbits['d'] = ZOR_FLAG_DIRECTORY;
		flagbits['f'] = ZOR_FLAG_PLAIN_FILE;
		flagbits['m'] = ZOR_FLAG_SPACE_MAP;
		flagbits['z'] = ZOR_FLAG_ZAP;
		flagbits['A'] = ZOR_FLAG_ALL_TYPES;

		if (argc > 0 && dump_opt['d']) {
			zopt_object_args = argc;
			zopt_object_ranges = calloc(zopt_object_args,
			    sizeof (zopt_object_range_t));
			for (unsigned i = 0; i < zopt_object_args; i++) {
				int err;
				const char *msg = NULL;

				err = parse_object_range(argv[i],
				    &zopt_object_ranges[i], &msg);
				if (err != 0)
					fatal("Bad object or range: '%s': %s\n",
					    argv[i], msg ?: "");
			}
		} else if (argc > 0 && dump_opt['m']) {
			zopt_metaslab_args = argc;
			zopt_metaslab = calloc(zopt_metaslab_args,
			    sizeof (uint64_t));
			for (unsigned i = 0; i < zopt_metaslab_args; i++) {
				errno = 0;
				zopt_metaslab[i] = strtoull(argv[i], NULL, 0);
				if (zopt_metaslab[i] == 0 && errno != 0)
					fatal("bad number %s: %s", argv[i],
					    strerror(errno));
			}
		}
		if (dump_opt['B']) {
			dump_backup(target, objset_id,
			    argc > 0 ? argv[0] : NULL);
		} else if (os != NULL) {
			dump_objset(os);
		} else if (zopt_object_args > 0 && !dump_opt['m']) {
			dump_objset(spa->spa_meta_objset);
		} else {
			dump_zpool(spa);
		}
	} else {
		flagbits['b'] = ZDB_FLAG_PRINT_BLKPTR;
		flagbits['c'] = ZDB_FLAG_CHECKSUM;
		flagbits['d'] = ZDB_FLAG_DECOMPRESS;
		flagbits['e'] = ZDB_FLAG_BSWAP;
		flagbits['g'] = ZDB_FLAG_GBH;
		flagbits['i'] = ZDB_FLAG_INDIRECT;
		flagbits['r'] = ZDB_FLAG_RAW;
		flagbits['v'] = ZDB_FLAG_VERBOSE;

		for (int i = 0; i < argc; i++)
			zdb_read_block(argv[i], spa);
	}

	if (dump_opt['k']) {
		free(checkpoint_pool);
		if (!target_is_spa)
			free(checkpoint_target);
	}

fini:
	if (spa != NULL)
		zdb_ddt_cleanup(spa);

	if (os != NULL) {
		close_objset(os, FTAG);
	} else if (spa != NULL) {
		spa_close(spa, FTAG);
	}

	fuid_table_destroy();

	dump_debug_buffer();

	if (kernel_init_done)
		kernel_fini();

	if (corruption_found && error == 0)
		error = 3;

	return (error);
}