xref: /freebsd-12.1/cddl/contrib/opensolaris/cmd/zdb/zdb.c (revision 0e376963)

/*
 * 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 http://www.opensolaris.org/os/licensing.
 * 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, 2017 by Delphix. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 * Copyright 2017 Nexenta Systems, Inc.
 * Copyright 2017 RackTop Systems.
 */

#include <stdio.h>
#include <unistd.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <ctype.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/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/dbuf.h>
#include <sys/zil.h>
#include <sys/zil_impl.h>
#include <sys/stat.h>
#include <sys/resource.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/ddt.h>
#include <sys/zfeature.h>
#include <sys/abd.h>
#include <sys/blkptr.h>
#include <sys/dsl_scan.h>
#include <zfs_comutil.h>
#include <libcmdutils.h>
#undef verify
#include <libzfs.h>

#include "zdb.h"

#define	ZDB_COMPRESS_NAME(idx) ((idx) < ZIO_COMPRESS_FUNCTIONS ?	\
	zio_compress_table[(idx)].ci_name : "UNKNOWN")
#define	ZDB_CHECKSUM_NAME(idx) ((idx) < ZIO_CHECKSUM_FUNCTIONS ?	\
	zio_checksum_table[(idx)].ci_name : "UNKNOWN")
#define	ZDB_OT_NAME(idx) ((idx) < DMU_OT_NUMTYPES ?	\
	dmu_ot[(idx)].ot_name : DMU_OT_IS_VALID(idx) ?	\
	dmu_ot_byteswap[DMU_OT_BYTESWAP(idx)].ob_name : "UNKNOWN")
#define	ZDB_OT_TYPE(idx) ((idx) < DMU_OT_NUMTYPES ? (idx) :		\
	(idx) == DMU_OTN_ZAP_DATA || (idx) == DMU_OTN_ZAP_METADATA ?	\
	DMU_OT_ZAP_OTHER : \
	(idx) == DMU_OTN_UINT64_DATA || (idx) == DMU_OTN_UINT64_METADATA ? \
	DMU_OT_UINT64_OTHER : DMU_OT_NUMTYPES)

#ifndef lint
extern int reference_tracking_enable;
extern boolean_t zfs_recover;
extern uint64_t zfs_arc_max, zfs_arc_meta_limit;
extern int zfs_vdev_async_read_max_active;
extern boolean_t spa_load_verify_dryrun;
extern int aok;
#else
int reference_tracking_enable;
boolean_t zfs_recover;
uint64_t zfs_arc_max, zfs_arc_meta_limit;
int zfs_vdev_async_read_max_active;
boolean_t spa_load_verify_dryrun;
int aok;
#endif

static const char cmdname[] = "zdb";
uint8_t dump_opt[256];

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

static uint64_t *zopt_object = NULL;
static unsigned zopt_objects = 0;
static libzfs_handle_t *g_zfs;
static uint64_t max_inflight = 1000;
static int leaked_objects = 0;

static void snprintf_blkptr_compact(char *, size_t, const blkptr_t *);
static void mos_obj_refd(uint64_t);

/*
 * These libumem hooks provide a reasonable set of defaults for the allocator's
 * debugging facilities.
 */
const char *
_umem_debug_init()
{
	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 [-AbcdDFGhikLMPsvX] [-e [-V] [-p <path> ...]] "
	    "[-I <inflight I/Os>]\n"
	    "\t\t[-o <var>=<value>]... [-t <txg>] [-U <cache>] [-x <dumpdir>]\n"
	    "\t\t[<poolname> [<object> ...]]\n"
	    "\t%s [-AdiPv] [-e [-V] [-p <path> ...]] [-U <cache>] <dataset> "
	    "[<object> ...]\n"
	    "\t%s -C [-A] [-U <cache>]\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 <dataset> <path>\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);

	(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 are specified, only "
	    "those objects are dumped\n\n");
	(void) fprintf(stderr, "    Options to control amount of output:\n");
	(void) fprintf(stderr, "        -b block statistics\n");
	(void) fprintf(stderr, "        -c checksum all metadata (twice for "
	    "all data) blocks\n");
	(void) fprintf(stderr, "        -C config (or cachefile if alone)\n");
	(void) fprintf(stderr, "        -d dataset(s)\n");
	(void) fprintf(stderr, "        -D dedup statistics\n");
	(void) fprintf(stderr, "        -E decode and display block from an "
	    "embedded block pointer\n");
	(void) fprintf(stderr, "        -h pool history\n");
	(void) fprintf(stderr, "        -i intent logs\n");
	(void) fprintf(stderr, "        -l read label contents\n");
	(void) fprintf(stderr, "        -k examine the checkpointed state "
	    "of the pool\n");
	(void) fprintf(stderr, "        -L disable leak tracking (do not "
	    "load spacemaps)\n");
	(void) fprintf(stderr, "        -m metaslabs\n");
	(void) fprintf(stderr, "        -M metaslab groups\n");
	(void) fprintf(stderr, "        -O perform object lookups by path\n");
	(void) fprintf(stderr, "        -R read and display block from a "
	    "device\n");
	(void) fprintf(stderr, "        -s report stats on zdb's I/O\n");
	(void) fprintf(stderr, "        -S simulate dedup to measure effect\n");
	(void) fprintf(stderr, "        -v verbose (applies to all "
	    "others)\n\n");
	(void) fprintf(stderr, "    Below options are intended for use "
	    "with other options:\n");
	(void) fprintf(stderr, "        -A ignore assertions (-A), enable "
	    "panic recovery (-AA) or both (-AAA)\n");
	(void) fprintf(stderr, "        -e pool is exported/destroyed/"
	    "has altroot/not in a cachefile\n");
	(void) fprintf(stderr, "        -F attempt automatic rewind within "
	    "safe range of transaction groups\n");
	(void) fprintf(stderr, "        -G dump zfs_dbgmsg buffer before "
	    "exiting\n");
	(void) fprintf(stderr, "        -I <number of inflight I/Os> -- "
	    "specify the maximum number of "
	    "checksumming I/Os [default is 200]\n");
	(void) fprintf(stderr, "        -o <variable>=<value> set global "
	    "variable to an unsigned 32-bit integer value\n");
	(void) fprintf(stderr, "        -p <path> -- use one or more with "
	    "-e to specify path to vdev dir\n");
	(void) fprintf(stderr, "        -P print numbers in parseable form\n");
	(void) fprintf(stderr, "        -q don't print label contents\n");
	(void) fprintf(stderr, "        -t <txg> -- highest txg to use when "
	    "searching for uberblocks\n");
	(void) fprintf(stderr, "        -u uberblock\n");
	(void) fprintf(stderr, "        -U <cachefile_path> -- use alternate "
	    "cachefile\n");
	(void) fprintf(stderr, "        -V do verbatim import\n");
	(void) fprintf(stderr, "        -x <dumpdir> -- "
	    "dump all read blocks into specified directory\n");
	(void) fprintf(stderr, "        -X attempt extreme rewind (does not "
	    "work with dataset)\n\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");
	exit(1);
}

static void
dump_debug_buffer()
{
	if (dump_opt['G']) {
		(void) printf("\n");
		zfs_dbgmsg_print("zdb");
	}
}

/*
 * 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();

	exit(1);
}

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

	VERIFY(0 == dmu_read(os, object, 0, nvsize, packed, DMU_READ_PREFETCH));

	VERIFY(nvlist_unpack(packed, nvsize, &nv, 0) == 0);

	umem_free(packed, nvsize);

	dump_nvlist(nv, 8);

	nvlist_free(nv);
}

/* ARGSUSED */
static void
dump_history_offsets(objset_t *os, uint64_t object, void *data, size_t 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, sizeof (buf));
}

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] > max)
			max = histo[i];
		if (histo[i] > 0 && i > maxidx)
			maxidx = i;
		if (histo[i] > 0 && 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);
}

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

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

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

/*ARGSUSED*/
static void
dump_uint64(objset_t *os, uint64_t object, void *data, size_t size)
{
}

/*ARGSUSED*/
static void
dump_zap(objset_t *os, uint64_t object, void *data, size_t size)
{
	zap_cursor_t zc;
	zap_attribute_t attr;
	void *prop;
	unsigned i;

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

	for (zap_cursor_init(&zc, os, object);
	    zap_cursor_retrieve(&zc, &attr) == 0;
	    zap_cursor_advance(&zc)) {
		(void) printf("\t\t%s = ", attr.za_name);
		if (attr.za_num_integers == 0) {
			(void) printf("\n");
			continue;
		}
		prop = umem_zalloc(attr.za_num_integers *
		    attr.za_integer_length, UMEM_NOFAIL);
		(void) zap_lookup(os, object, attr.za_name,
		    attr.za_integer_length, attr.za_num_integers, prop);
		if (attr.za_integer_length == 1) {
			(void) printf("%s", (char *)prop);
		} else {
			for (i = 0; i < attr.za_num_integers; i++) {
				switch (attr.za_integer_length) {
				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, attr.za_num_integers * attr.za_integer_length);
	}
	zap_cursor_fini(&zc);
}

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

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

	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 >= sizeof (*bpop)) {
		(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 (dump_opt['d'] < 5)
		return;

	for (uint64_t 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);
		(void) printf("\t%s\n", blkbuf);
	}
}

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

	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 (uint64_t i = 0; i < doi.doi_max_offset / 8; i++) {
		if (subobjs[i] != 0)
			last_nonzero = i;
	}

	for (int64_t i = 0; i <= last_nonzero; i++) {
		(void) printf("\t%llu\n", (longlong_t)subobjs[i]);
	}
	kmem_free(subobjs, doi.doi_max_offset);
}

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

/*ARGSUSED*/
static void
dump_sa_attrs(objset_t *os, uint64_t object, void *data, size_t size)
{
	zap_cursor_t zc;
	zap_attribute_t attr;

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

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

/*ARGSUSED*/
static void
dump_sa_layouts(objset_t *os, uint64_t object, void *data, size_t size)
{
	zap_cursor_t zc;
	zap_attribute_t attr;
	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, &attr) == 0;
	    zap_cursor_advance(&zc)) {
		(void) printf("\t\t%s = [", attr.za_name);
		if (attr.za_num_integers == 0) {
			(void) printf("\n");
			continue;
		}

		VERIFY(attr.za_integer_length == 2);
		layout_attrs = umem_zalloc(attr.za_num_integers *
		    attr.za_integer_length, UMEM_NOFAIL);

		VERIFY(zap_lookup(os, object, attr.za_name,
		    attr.za_integer_length,
		    attr.za_num_integers, layout_attrs) == 0);

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

/*ARGSUSED*/
static void
dump_zpldir(objset_t *os, uint64_t object, void *data, size_t size)
{
	zap_cursor_t zc;
	zap_attribute_t attr;
	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, &attr) == 0;
	    zap_cursor_advance(&zc)) {
		(void) printf("\t\t%s = %lld (type: %s)\n",
		    attr.za_name, ZFS_DIRENT_OBJ(attr.za_first_integer),
		    typenames[ZFS_DIRENT_TYPE(attr.za_first_integer)]);
	}
	zap_cursor_fini(&zc);
}

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)
{
	int refcount = 0;

	uint64_t obsolete_sm_obj = vdev_obsolete_sm_object(vd);
	if (vd->vdev_top == vd && obsolete_sm_obj != 0) {
		dmu_object_info_t doi;
		VERIFY0(dmu_object_info(vd->vdev_spa->spa_meta_objset,
		    obsolete_sm_obj, &doi));
		if (doi.doi_bonus_size == sizeof (space_map_phys_t)) {
			refcount++;
		}
	} else {
		ASSERT3P(vd->vdev_obsolete_sm, ==, NULL);
		ASSERT3U(obsolete_sm_obj, ==, 0);
	}
	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
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);

	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)
{
	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_phys->smp_object);
	(void) printf("  smp_objsize = 0x%llx\n",
	    (longlong_t)sm->sm_phys->smp_objsize);
	(void) printf("  smp_alloc = 0x%llx\n",
	    (longlong_t)sm->sm_phys->smp_alloc);

	/*
	 * Print out the freelist entries in both encoded and decoded form.
	 */
	uint8_t mapshift = sm->sm_shift;
	int64_t alloc = 0;
	uint64_t word;
	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)) {
			(void) printf("\t    [%6llu] %s: txg %llu, pass %llu\n",
			    (u_longlong_t)(offset / sizeof (word)),
			    ddata[SM_DEBUG_ACTION_DECODE(word)],
			    (u_longlong_t)SM_DEBUG_TXG_DECODE(word),
			    (u_longlong_t)SM_DEBUG_SYNCPASS_DECODE(word));
			continue;
		}

		uint8_t words;
		char entry_type;
		uint64_t entry_off, entry_run, entry_vdev = SM_NO_VDEVID;

		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;
			words = 1;
		} 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);
			VERIFY0(dmu_read(os, space_map_object(sm), offset,
			    sizeof (extra_word), &extra_word,
			    DMU_READ_PREFETCH));

			ASSERT3U(offset, <=, space_map_length(sm));

			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;
			words = 2;
		}

		(void) printf("\t    [%6llu]    %c  range:"
		    " %010llx-%010llx  size: %06llx vdev: %06llu words: %u\n",
		    (u_longlong_t)(offset / sizeof (word)),
		    entry_type, (u_longlong_t)entry_off,
		    (u_longlong_t)(entry_off + entry_run),
		    (u_longlong_t)entry_run,
		    (u_longlong_t)entry_vdev, words);

		if (entry_type == 'A')
			alloc += entry_run;
		else
			alloc -= entry_run;
	}
	if ((uint64_t)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];
	range_tree_t *rt = msp->ms_allocatable;
	avl_tree_t *t = &msp->ms_allocatable_by_size;
	int free_pct = range_tree_space(rt) * 100 / msp->ms_size;

	/* max sure nicenum has enough space */
	CTASSERT(sizeof (maxbuf) >= NN_NUMBUF_SZ);

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

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

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['m'] > 2 && !dump_opt['L']) {
		mutex_enter(&msp->ms_lock);
		metaslab_load_wait(msp);
		if (!msp->ms_loaded) {
			VERIFY0(metaslab_load(msp));
			range_tree_stat_verify(msp->ms_allocatable);
		}
		dump_metaslab_stats(msp);
		metaslab_unload(msp);
		mutex_exit(&msp->ms_lock);
	}

	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['d'] > 5 || dump_opt['m'] > 3) {
		ASSERT(msp->ms_size == (1ULL << vd->vdev_ms_shift));

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

static void
print_vdev_metaslab_header(vdev_t *vd)
{
	(void) printf("\tvdev %10llu\n\t%-10s%5llu   %-19s   %-15s   %-10s\n",
	    (u_longlong_t)vd->vdev_id,
	    "metaslabs", (u_longlong_t)vd->vdev_ms_count,
	    "offset", "spacemap", "free");
	(void) printf("\t%15s   %19s   %15s   %10s\n",
	    "---------------", "-------------------",
	    "---------------", "-------------");
}

static void
dump_metaslab_groups(spa_t *spa)
{
	vdev_t *rvd = spa->spa_root_vdev;
	metaslab_class_t *mc = spa_normal_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->mg_class != mc)
			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, 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, 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) {
		ASSERT3P(vib, ==, NULL);
		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 = vdev_obsolete_sm_object(vd);
	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 (!dump_opt['d'] && zopt_objects > 0) {
		c = zopt_object[0];

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

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

			for (m = 1; m < zopt_objects; m++) {
				if (zopt_object[m] < vd->vdev_ms_count)
					dump_metaslab(
					    vd->vdev_ms[zopt_object[m]]);
				else
					(void) fprintf(stderr, "bad metaslab "
					    "number %llu\n",
					    (u_longlong_t)zopt_object[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_dde(const ddt_t *ddt, const ddt_entry_t *dde, uint64_t index)
{
	const ddt_phys_t *ddp = dde->dde_phys;
	const ddt_key_t *ddk = &dde->dde_key;
	const char *types[4] = { "ditto", "single", "double", "triple" };
	char blkbuf[BP_SPRINTF_LEN];
	blkptr_t blk;

	for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
		if (ddp->ddp_phys_birth == 0)
			continue;
		ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
		snprintf_blkptr(blkbuf, sizeof (blkbuf), &blk);
		(void) printf("index %llx refcnt %llu %s %s\n",
		    (u_longlong_t)index, (u_longlong_t)ddp->ddp_refcnt,
		    types[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(ddt_t *ddt, enum ddt_type type, enum ddt_class class)
{
	char name[DDT_NAMELEN];
	ddt_entry_t dde;
	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;
	ASSERT(error == 0);

	error = ddt_object_count(ddt, type, class, &count);
	ASSERT(error == 0);
	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: %llu entries, size %llu on disk, %llu in core\n",
	    name,
	    (u_longlong_t)count,
	    (u_longlong_t)(dspace / count),
	    (u_longlong_t)(mspace / count));

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

	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, &dde)) == 0)
		dump_dde(ddt, &dde, walk);

	ASSERT3U(error, ==, ENOENT);

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

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

	bzero(&ddh_total, sizeof (ddh_total));
	bzero(&dds_total, sizeof (dds_total));

	for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
		ddt_t *ddt = spa->spa_ddt[c];
		for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
			for (enum ddt_class class = 0; class < DDT_CLASSES;
			    class++) {
				dump_ddt(ddt, type, class);
			}
		}
	}

	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);
}

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++) {
		range_tree_t *rt = vd->vdev_dtl[t];
		if (range_tree_space(rt) == 0)
			continue;
		(void) snprintf(prefix, sizeof (prefix), "\t%*s%s",
		    indent + 2, "", name[t]);
		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);
}

/* from spa_history.c: spa_history_create_obj() */
#define	HIS_BUF_LEN_DEF	(128 << 10)
#define	HIS_BUF_LEN_MAX	(1 << 30)

static void
dump_history(spa_t *spa)
{
	nvlist_t **events = NULL;
	char *buf = NULL;
	uint64_t bufsize = HIS_BUF_LEN_DEF;
	uint64_t resid, len, off = 0;
	uint_t num = 0;
	int error;
	time_t tsec;
	struct tm t;
	char tbuf[30];
	char internalstr[MAXPATHLEN];

	if ((buf = malloc(bufsize)) == NULL)
		(void) fprintf(stderr, "Unable to read history: "
		    "out of memory\n");
	do {
		len = bufsize;

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

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

		/*
		 * If the history block is too big, double the buffer
		 * size and try again.
		 */
		if (resid == len) {
			free(buf);
			buf = NULL;

			bufsize <<= 1;
			if ((bufsize >= HIS_BUF_LEN_MAX) ||
			    ((buf = malloc(bufsize)) == NULL)) {
				(void) fprintf(stderr, "Unable to read history: "
				    "out of memory\n");
				return;
			}
		}
	} while (len != 0);
	free(buf);

	(void) printf("\nHistory:\n");
	for (unsigned i = 0; i < num; i++) {
		uint64_t time, txg, ievent;
		char *cmd, *intstr;
		boolean_t printed = B_FALSE;

		if (nvlist_lookup_uint64(events[i], ZPOOL_HIST_TIME,
		    &time) != 0)
			goto next;
		if (nvlist_lookup_string(events[i], ZPOOL_HIST_CMD,
		    &cmd) != 0) {
			if (nvlist_lookup_uint64(events[i],
			    ZPOOL_HIST_INT_EVENT, &ievent) != 0)
				goto next;
			verify(nvlist_lookup_uint64(events[i],
			    ZPOOL_HIST_TXG, &txg) == 0);
			verify(nvlist_lookup_string(events[i],
			    ZPOOL_HIST_INT_STR, &intstr) == 0);
			if (ievent >= ZFS_NUM_LEGACY_HISTORY_EVENTS)
				goto next;

			(void) snprintf(internalstr,
			    sizeof (internalstr),
			    "[internal %s txg:%ju] %s",
			    zfs_history_event_names[ievent], (uintmax_t)txg,
			    intstr);
			cmd = internalstr;
		}
		tsec = time;
		(void) localtime_r(&tsec, &t);
		(void) strftime(tbuf, sizeof (tbuf), "%F.%T", &t);
		(void) printf("%s %s\n", tbuf, cmd);
		printed = B_TRUE;

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

/*ARGSUSED*/
static void
dump_dnode(objset_t *os, uint64_t object, void *data, size_t 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_blkptr_compact(char *blkbuf, size_t buflen, const blkptr_t *bp)
{
	const dva_t *dva = bp->blk_dva;
	int ndvas = dump_opt['d'] > 5 ? BP_GET_NDVAS(bp) : 1;

	if (dump_opt['b'] >= 6) {
		snprintf_blkptr(blkbuf, buflen, bp);
		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->blk_birth);
		return;
	}

	blkbuf[0] = '\0';
	for (int i = 0; i < ndvas; i++)
		(void) snprintf(blkbuf + strlen(blkbuf),
		    buflen - strlen(blkbuf), "%llu:%llx:%llx ",
		    (u_longlong_t)DVA_GET_VDEV(&dva[i]),
		    (u_longlong_t)DVA_GET_OFFSET(&dva[i]),
		    (u_longlong_t)DVA_GET_ASIZE(&dva[i]));

	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->blk_birth);
	} 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->blk_birth,
		    (u_longlong_t)BP_PHYSICAL_BIRTH(bp));
	}
}

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

	if (!BP_IS_EMBEDDED(bp)) {
		ASSERT3U(BP_GET_TYPE(bp), ==, dnp->dn_type);
		ASSERT3U(BP_GET_LEVEL(bp), ==, zb->zb_level);
	}

	(void) printf("%16llx ", (u_longlong_t)blkid2offset(dnp, bp, zb));

	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);
	(void) printf("%s\n", blkbuf);
}

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

	if (bp->blk_birth == 0)
		return (0);

	print_indirect(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;

		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)
			ASSERT3U(fill, ==, BP_GET_FILL(bp));
		arc_buf_destroy(buf, &buf);
	}

	return (err);
}

/*ARGSUSED*/
static void
dump_indirect(dnode_t *dn)
{
	dnode_phys_t *dnp = dn->dn_phys;
	int j;
	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 (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");
}

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

	/* make sure nicenum has enough space */
	CTASSERT(sizeof (nice) >= NN_NUMBUF_SZ);

	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);
}

/*ARGSUSED*/
static void
dump_dsl_dataset(objset_t *os, uint64_t object, void *data, size_t size)
{
	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 */
	CTASSERT(sizeof (used) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (compressed) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (uncompressed) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (unique) >= NN_NUMBUF_SZ);

	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);
}

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

	if (bp->blk_birth != 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 */
	CTASSERT(sizeof (bytes) >= NN_NUMBUF_SZ);

	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);
}

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

	ASSERT(bp->blk_birth != 0);
	snprintf_blkptr_compact(blkbuf, sizeof (blkbuf), bp);
	(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];

	/* make sure nicenum has enough space */
	CTASSERT(sizeof (bytes) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (comp) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (uncomp) >= NN_NUMBUF_SZ);

	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));
		(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 (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);
				continue;
			}
			dump_full_bpobj(&subbpo, "subobj", indent + 1);
			bpobj_close(&subbpo);
		}
	} 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 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);
				continue;
			}
			bpobj_count_refd(&subbpo);
			bpobj_close(&subbpo);
		}
	}
}

static void
dump_deadlist(dsl_deadlist_t *dl)
{
	dsl_deadlist_entry_t *dle;
	uint64_t unused;
	char bytes[32];
	char comp[32];
	char uncomp[32];
	uint64_t empty_bpobj =
	    dmu_objset_spa(dl->dl_os)->spa_dsl_pool->dp_empty_bpobj;

	/* force the tree to be loaded */
	dsl_deadlist_space_range(dl, 0, UINT64_MAX, &unused, &unused, &unused);

	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);
		for (dle = avl_first(&dl->dl_tree); dle;
		    dle = AVL_NEXT(&dl->dl_tree, dle)) {
			if (dle->dle_bpobj.bpo_object != empty_bpobj)
				bpobj_count_refd(&dle->dle_bpobj);
		}
	}

	/* make sure nicenum has enough space */
	CTASSERT(sizeof (bytes) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (comp) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (uncomp) >= NN_NUMBUF_SZ);

	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));
	(void) printf("\n    Deadlist: %s (%s/%s comp)\n",
	    bytes, comp, uncomp);

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

	(void) printf("\n");

	for (dle = avl_first(&dl->dl_tree); dle;
	    dle = AVL_NEXT(&dl->dl_tree, dle)) {
		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);
		}
	}
}

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, dmu_objset_type_t type, void *tag, objset_t **osp)
{
	int err;
	uint64_t sa_attrs = 0;
	uint64_t version = 0;

	VERIFY3P(sa_os, ==, NULL);
	err = dmu_objset_own(path, type, B_TRUE, tag, osp);
	if (err != 0) {
		(void) fprintf(stderr, "failed to own dataset '%s': %s\n", path,
		    strerror(err));
		return (err);
	}

	if (dmu_objset_type(*osp) == DMU_OST_ZFS) {
		(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));
			dmu_objset_disown(*osp, tag);
			*osp = NULL;
		}
	}
	sa_os = *osp;

	return (0);
}

static void
close_objset(objset_t *os, void *tag)
{
	VERIFY3P(os, ==, sa_os);
	if (os->os_sa != NULL)
		sa_tear_down(os);
	dmu_objset_disown(os, tag);
	sa_attr_table = NULL;
	sa_os = NULL;
}

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

/*
 * 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)) {
		char *domain;

		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 */
		VERIFY(zap_lookup(os, MASTER_NODE_OBJ, ZFS_FUID_TABLES,
		    8, 1, &fuid_obj) == 0);
		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");
}

/*ARGSUSED*/
static void
dump_znode(objset_t *os, uint64_t object, void *data, size_t 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);
	}
	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 (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);
	sa_handle_destroy(hdl);
}

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

/*ARGSUSED*/
static void
dump_dmu_objset(objset_t *os, uint64_t object, void *data, size_t 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 used		*/
	dump_zap,		/* ZFS user/group 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 void
dump_object(objset_t *os, uint64_t object, int verbosity, int *print_header)
{
	dmu_buf_t *db = NULL;
	dmu_object_info_t doi;
	dnode_t *dn;
	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 */
	CTASSERT(sizeof (iblk) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (dblk) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (lsize) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (asize) >= NN_NUMBUF_SZ);
	CTASSERT(sizeof (bonus_size) >= NN_NUMBUF_SZ);

	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);
	} 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);
	}
	dmu_object_info_from_dnode(dn, &doi);

	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) sprintf(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), " (K=%s)",
		    ZDB_CHECKSUM_NAME(doi.doi_checksum));
	}

	if (doi.doi_compress != ZIO_COMPRESS_INHERIT || verbosity >= 6) {
		(void) snprintf(aux + strlen(aux), sizeof (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\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_SPILL_BLKPTR) ?
		    "SPILL_BLKPTR" : "");
		(void) printf("\tdnode maxblkid: %llu\n",
		    (longlong_t)dn->dn_phys->dn_maxblkid);

		object_viewer[ZDB_OT_TYPE(doi.doi_bonus_type)](os, object,
		    bonus, bsize);
		object_viewer[ZDB_OT_TYPE(doi.doi_type)](os, object, NULL, 0);
		*print_header = 1;
	}

	if (verbosity >= 5)
		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 */
			CTASSERT(sizeof (segsize) >= NN_NUMBUF_SZ);
			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;
		}
	}

	if (db != NULL)
		dmu_buf_rele(db, 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);
}

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);

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

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

static void
dump_dir(objset_t *os)
{
	dmu_objset_stats_t dds;
	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'];
	int print_header = 1;
	unsigned i;
	int error;

	/* make sure nicenum has enough space */
	CTASSERT(sizeof (numbuf) >= NN_NUMBUF_SZ);

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

	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)" : "");

	if (zopt_objects != 0) {
		for (i = 0; i < zopt_objects; i++)
			dump_object(os, zopt_object[i], verbosity,
			    &print_header);
		(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_deadlist(&ds->ds_deadlist);

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

	if (verbosity < 2)
		return;

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

	dump_object(os, 0, verbosity, &print_header);
	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);
		dump_object(os, DMU_GROUPUSED_OBJECT, verbosity, &print_header);
	}

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

	(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, asctime(localtime(&timestamp)));
	if (dump_opt['u'] >= 3) {
		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("%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) fprintf(stderr, "cannot open '%s': %s\n", cachefile,
		    strerror(errno));
		exit(1);
	}

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

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

	(void) close(fd);

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

	free(buf);

	dump_nvlist(config, 0);

	nvlist_free(config);
}

#define	ZDB_MAX_UB_HEADER_SIZE 32

static void
dump_label_uberblocks(vdev_label_t *lbl, uint64_t ashift)
{
	vdev_t vd;
	vdev_t *vdp = &vd;
	char header[ZDB_MAX_UB_HEADER_SIZE];

	vd.vdev_ashift = ashift;
	vdp->vdev_top = vdp;

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

		if (uberblock_verify(ub))
			continue;
		(void) snprintf(header, ZDB_MAX_UB_HEADER_SIZE,
		    "Uberblock[%d]\n", i);
		dump_uberblock(ub, header, "");
	}
}

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)
{
	int err;
	int header = 1;
	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));
		/*FALLTHROUGH*/
	case DMU_OT_PLAIN_FILE_CONTENTS:
		dump_object(os, child_obj, dump_opt['v'], &header);
		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)
{
	int err;
	objset_t *os;
	uint64_t root_obj;

	err = open_objset(ds, DMU_OST_ZFS, 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));
		dmu_objset_disown(os, FTAG);
		return (EINVAL);
	}

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

	err = dump_path_impl(os, root_obj, path);

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

static int
dump_label(const char *dev)
{
	int fd;
	vdev_label_t label;
	char path[MAXPATHLEN];
	char *buf = label.vl_vdev_phys.vp_nvlist;
	size_t buflen = sizeof (label.vl_vdev_phys.vp_nvlist);
	struct stat64 statbuf;
	uint64_t psize, ashift;
	boolean_t label_found = B_FALSE;

	(void) strlcpy(path, dev, sizeof (path));
	if (dev[0] == '/') {
		if (strncmp(dev, ZFS_DISK_ROOTD,
		    strlen(ZFS_DISK_ROOTD)) == 0) {
			(void) snprintf(path, sizeof (path), "%s%s",
			    ZFS_RDISK_ROOTD, dev + strlen(ZFS_DISK_ROOTD));
		}
	} else if (stat64(path, &statbuf) != 0) {
		char *s;

		(void) snprintf(path, sizeof (path), "%s%s", ZFS_RDISK_ROOTD,
		    dev);
		if (((s = strrchr(dev, 's')) == NULL &&
		    (s = strchr(dev, 'p')) == NULL) ||
		    !isdigit(*(s + 1)))
			(void) strlcat(path, "s0", sizeof (path));
	}

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

	if (fstat64(fd, &statbuf) != 0) {
		(void) fprintf(stderr, "failed to stat '%s': %s\n", path,
		    strerror(errno));
		(void) close(fd);
		exit(1);
	}

	if (S_ISBLK(statbuf.st_mode)) {
		(void) fprintf(stderr,
		    "cannot use '%s': character device required\n", path);
		(void) close(fd);
		exit(1);
	}

	psize = statbuf.st_size;
	psize = P2ALIGN(psize, (uint64_t)sizeof (vdev_label_t));

	for (int l = 0; l < VDEV_LABELS; l++) {
		nvlist_t *config = NULL;

		if (!dump_opt['q']) {
			(void) printf("------------------------------------\n");
			(void) printf("LABEL %d\n", l);
			(void) printf("------------------------------------\n");
		}

		if (pread64(fd, &label, sizeof (label),
		    vdev_label_offset(psize, l, 0)) != sizeof (label)) {
			if (!dump_opt['q'])
				(void) printf("failed to read label %d\n", l);
			continue;
		}

		if (nvlist_unpack(buf, buflen, &config, 0) != 0) {
			if (!dump_opt['q'])
				(void) printf("failed to unpack label %d\n", l);
			ashift = SPA_MINBLOCKSHIFT;
		} else {
			nvlist_t *vdev_tree = NULL;

			if (!dump_opt['q'])
				dump_nvlist(config, 4);
			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;
			nvlist_free(config);
			label_found = B_TRUE;
		}
		if (dump_opt['u'])
			dump_label_uberblocks(&label, ashift);
	}

	(void) close(fd);

	return (label_found ? 0 : 2);
}

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

/*ARGSUSED*/
static int
dump_one_dir(const char *dsname, void *arg)
{
	int error;
	objset_t *os;

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

	for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
		if (!dmu_objset_ds(os)->ds_feature_inuse[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++;
	}

	dump_dir(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_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

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_embedded_blocks[NUM_BP_EMBEDDED_TYPES];
	uint64_t	zcb_embedded_histogram[NUM_BP_EMBEDDED_TYPES]
	    [BPE_PAYLOAD_SIZE];
	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;
} zdb_cb_t;

static void
zdb_count_block(zdb_cb_t *zcb, zilog_t *zilog, const blkptr_t *bp,
    dmu_object_type_t type)
{
	uint64_t refcnt = 0;

	ASSERT(type < ZDB_OT_TOTAL);

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

	for (int 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++;
			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++;
			break;
		}

	}

	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;
	}

	if (dump_opt['L'])
		return;

	if (BP_GET_DEDUP(bp)) {
		ddt_t *ddt;
		ddt_entry_t *dde;

		ddt = ddt_select(zcb->zcb_spa, bp);
		ddt_enter(ddt);
		dde = ddt_lookup(ddt, bp, B_FALSE);

		if (dde == NULL) {
			refcnt = 0;
		} else {
			ddt_phys_t *ddp = ddt_phys_select(dde, bp);
			ddt_phys_decref(ddp);
			refcnt = ddp->ddp_refcnt;
			if (ddt_phys_total_refcnt(dde) == 0)
				ddt_remove(ddt, dde);
		}
		ddt_exit(ddt);
	}

	VERIFY3U(zio_wait(zio_claim(NULL, zcb->zcb_spa,
	    refcnt ? 0 : spa_min_claim_txg(zcb->zcb_spa),
	    bp, NULL, NULL, ZIO_FLAG_CANFAIL)), ==, 0);
}

/* ARGSUSED */
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;

	abd_free(zio->io_abd);

	mutex_enter(&spa->spa_scrub_lock);
	spa->spa_scrub_inflight--;
	spa->spa_load_verify_ios--;
	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);
}

/* ARGSUSED */
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 (bp == NULL)
		return (0);

	if (dump_opt['b'] >= 5 && bp->blk_birth > 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))
		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_ios > max_inflight)
			cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
		spa->spa_scrub_inflight++;
		spa->spa_load_verify_ios++;
		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;
		int kb_per_sec =
		    1 + bytes / (1 + ((now - zcb->zcb_start) / 1000 / 1000));
		int sec_remaining =
		    (zcb->zcb_totalasize - bytes) / 1024 / kb_per_sec;

		/* make sure nicenum has enough space */
		CTASSERT(sizeof (buf) >= NN_NUMBUF_SZ);

		zfs_nicenum(bytes, buf, sizeof (buf));
		(void) fprintf(stderr,
		    "\r%5s completed (%4dMB/s) "
		    "estimated time remaining: %uhr %02umin %02usec        ",
		    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 void
zdb_ddt_leak_init(spa_t *spa, zdb_cb_t *zcb)
{
	ddt_bookmark_t ddb;
	ddt_entry_t dde;
	int error;

	bzero(&ddb, sizeof (ddb));
	while ((error = ddt_walk(spa, &ddb, &dde)) == 0) {
		blkptr_t blk;
		ddt_phys_t *ddp = dde.dde_phys;

		if (ddb.ddb_class == DDT_CLASS_UNIQUE)
			return;

		ASSERT(ddt_phys_total_refcnt(&dde) > 1);

		for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
			if (ddp->ddp_phys_birth == 0)
				continue;
			ddt_bp_create(ddb.ddb_checksum,
			    &dde.dde_key, ddp, &blk);
			if (p == DDT_PHYS_DITTO) {
				zdb_count_block(zcb, NULL, &blk, ZDB_OT_DITTO);
			} else {
				zcb->zcb_dedup_asize +=
				    BP_GET_ASIZE(&blk) * (ddp->ddp_refcnt - 1);
				zcb->zcb_dedup_blocks++;
			}
		}
		if (!dump_opt['L']) {
			ddt_t *ddt = spa->spa_ddt[ddb.ddb_checksum];
			ddt_enter(ddt);
			VERIFY(ddt_lookup(ddt, &blk, B_TRUE) != NULL);
			ddt_exit(ddt);
		}
	}

	ASSERT(error == ENOENT);
}

/* ARGSUSED */
static void
claim_segment_impl_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset,
    uint64_t size, 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 (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;

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

		if (msp->ms_start >= vdev_indirect_mapping_max_offset(vim))
			break;

		ASSERT0(range_tree_space(svr->svr_allocd_segs));

		if (msp->ms_sm != NULL) {
			VERIFY0(space_map_load(msp->ms_sm,
			    svr->svr_allocd_segs, SM_ALLOC));

			/*
			 * Clear everything past what has been synced unless
			 * it's past the spacemap, because we have not allocated
			 * mappings for it yet.
			 */
			uint64_t vim_max_offset =
			    vdev_indirect_mapping_max_offset(vim);
			uint64_t sm_end = msp->ms_sm->sm_start +
			    msp->ms_sm->sm_size;
			if (sm_end > vim_max_offset)
				range_tree_clear(svr->svr_allocd_segs,
				    vim_max_offset, sm_end - vim_max_offset);
		}

		zcb->zcb_removing_size +=
		    range_tree_space(svr->svr_allocd_segs);
		range_tree_vacate(svr->svr_allocd_segs, claim_segment_cb, vd);
	}

	spa_config_exit(spa, SCL_CONFIG, FTAG);
}

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

	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;
	uint32_t *counts;

	EQUIV(vdev_obsolete_sm_object(vd) != 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));
		space_map_update(prev_obsolete_sm);
		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);
	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));
	space_map_update(checkpoint_sm);

	VERIFY0(space_map_iterate(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)
{
	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 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);
			metaslab_unload(msp);

			/*
			 * 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);
		}
	}
}

/*
 * 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);
	metaslab_unload(msp);

	/*
	 * 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);
		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)
{
	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().
		 */
		VERIFY0(vdev_metaslab_init(vd, 0));

		vdev_indirect_mapping_t *vim = 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']) {
		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;

		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);

		/* 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);
		}
	} else {
		/*
		 * If leak tracing is disabled, we still need to consider
		 * any checkpointed space in our space verification.
		 */
		zcb->zcb_checkpoint_size += spa_get_checkpoint_space(spa);
	}

	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
	zdb_ddt_leak_init(spa, zcb);
	spa_config_exit(spa, SCL_CONFIG, FTAG);
}

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;

	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 += 1 << vd->vdev_ashift) {
			if (range_tree_contains(msp->ms_allocatable,
			    offset + inner_offset, 1 << vd->vdev_ashift)) {
				obsolete_bytes += 1 << 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]);
		if (bytes_leaked != 0 &&
		    (vdev_obsolete_counts_are_precise(vd) ||
		    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);
	}

	if (!vdev_obsolete_counts_are_precise(vd) && 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)
{
	boolean_t leaks = B_FALSE;
	if (!dump_opt['L']) {
		vdev_t *rvd = spa->spa_root_vdev;
		for (unsigned c = 0; c < rvd->vdev_children; c++) {
			vdev_t *vd = rvd->vdev_child[c];
			metaslab_group_t *mg = vd->vdev_mg;

			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(mg, ==, msp->ms_group);

				/*
				 * 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) {
					range_tree_vacate(msp->ms_allocatable,
					    NULL, NULL);
				} else {
					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);
}

/* ARGSUSED */
static int
count_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *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);
}

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_HARD;
	boolean_t leaks = B_FALSE;

	bzero(&zcb, sizeof (zcb));
	(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 " : "");

	/*
	 * Load all space maps as SM_ALLOC maps, then traverse the pool
	 * claiming each block we discover.  If the pool is perfectly
	 * consistent, the space maps 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.
	 */
	zdb_leak_init(spa, &zcb);

	/*
	 * If there's a deferred-free bplist, process that first.
	 */
	(void) bpobj_iterate_nofree(&spa->spa_deferred_bpobj,
	    count_block_cb, &zcb, NULL);

	if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
		(void) bpobj_iterate_nofree(&spa->spa_dsl_pool->dp_free_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));
	}

	if (dump_opt['c'] > 1)
		flags |= TRAVERSE_PREFETCH_DATA;

	zcb.zcb_totalasize = metaslab_class_get_alloc(spa_normal_class(spa));
	zcb.zcb_start = zcb.zcb_lastprint = gethrtime();
	zcb.zcb_haderrors |= 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 (int i = 0; i < max_ncpus; i++) {
			(void) zio_wait(spa->spa_async_zio_root[i]);
			spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
			    ZIO_FLAG_GODFATHER);
		}
	}

	if (zcb.zcb_haderrors) {
		(void) printf("\nError counts:\n\n");
		(void) printf("\t%5s  %s\n", "errno", "count");
		for (int 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));
	total_found = tzb->zb_asize - zcb.zcb_dedup_asize +
	    zcb.zcb_removing_size + zcb.zcb_checkpoint_size;

	if (total_found == total_alloc) {
		if (!dump_opt['L'])
			(void) printf("\n\tNo leaks (block sum matches space"
			    " maps exactly)\n");
	} else {
		(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));
		leaks = B_TRUE;
	}

	if (tzb->zb_count == 0)
		return (2);

	(void) printf("\n");
	(void) printf("\tbp count:      %10llu\n",
	    (u_longlong_t)tzb->zb_count);
	(void) printf("\tganged count:  %10llu\n",
	    (longlong_t)tzb->zb_gangs);
	(void) printf("\tbp logical:    %10llu      avg: %6llu\n",
	    (u_longlong_t)tzb->zb_lsize,
	    (u_longlong_t)(tzb->zb_lsize / tzb->zb_count));
	(void) printf("\tbp physical:   %10llu      avg:"
	    " %6llu     compression: %6.2f\n",
	    (u_longlong_t)tzb->zb_psize,
	    (u_longlong_t)(tzb->zb_psize / tzb->zb_count),
	    (double)tzb->zb_lsize / tzb->zb_psize);
	(void) printf("\tbp allocated:  %10llu      avg:"
	    " %6llu     compression: %6.2f\n",
	    (u_longlong_t)tzb->zb_asize,
	    (u_longlong_t)(tzb->zb_asize / tzb->zb_count),
	    (double)tzb->zb_lsize / tzb->zb_asize);
	(void) printf("\tbp deduped:    %10llu    ref>1:"
	    " %6llu   deduplication: %6.2f\n",
	    (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("\tSPA allocated: %10llu     used: %5.2f%%\n",
	    (u_longlong_t)norm_alloc, 100.0 * norm_alloc / norm_space);

	for (bp_embedded_type_t 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);
	}

	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;
		(void) printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
		    "\t  avg\t comp\t%%Total\tType\n");

		for (t = 0; t <= ZDB_OT_TOTAL; t++) {
			char csize[32], lsize[32], psize[32], asize[32];
			char avg[32], gang[32];
			const char *typename;

			/* make sure nicenum has enough space */
			CTASSERT(sizeof (csize) >= NN_NUMBUF_SZ);
			CTASSERT(sizeof (lsize) >= NN_NUMBUF_SZ);
			CTASSERT(sizeof (psize) >= NN_NUMBUF_SZ);
			CTASSERT(sizeof (asize) >= NN_NUMBUF_SZ);
			CTASSERT(sizeof (avg) >= NN_NUMBUF_SZ);
			CTASSERT(sizeof (gang) >= NN_NUMBUF_SZ);

			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 (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);
				}
			}
		}
	}

	(void) printf("\n");

	if (leaks)
		return (2);

	if (zcb.zcb_haderrors)
		return (3);

	return (0);
}

typedef struct zdb_ddt_entry {
	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;

/* ARGSUSED */
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)
{
	avl_tree_t *t = arg;
	avl_index_t where;
	zdb_ddt_entry_t *zdde, zdde_search;

	if (bp == NULL || 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;
	ddt_stat_t dds_total;

	bzero(&ddh_total, sizeof (ddh_total));
	bzero(&dds_total, sizeof (dds_total));
	avl_create(&t, ddt_entry_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,
	    zdb_ddt_add_cb, &t);

	spa_config_exit(spa, SCL_CONFIG, FTAG);

	while ((zdde = avl_destroy_nodes(&t, &cookie)) != NULL) {
		ddt_stat_t dds;
		uint64_t refcnt = zdde->zdde_ref_blocks;
		ASSERT(refcnt != 0);

		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;

		ddt_stat_add(&ddh_total.ddh_stat[highbit64(refcnt) - 1],
		    &dds, 0);

		umem_free(zdde, sizeof (*zdde));
	}

	avl_destroy(&t);

	ddt_histogram_stat(&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));
			space_map_update(prev_obsolete_sm);
			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++;
			}
		}
		if (vdev_obsolete_counts_are_precise(vd)) {
			ASSERT(vic->vic_mapping_object != 0);
			precise_vdev_count++;
		}
		if (vdev_obsolete_sm_object(vd) != 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);
}

#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 appened 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, char **new_path)
{
	int error = 0;
	char *poolname, *bogus_name;

	/* If the target is not a pool, the extract the pool name */
	char *path_start = strchr(target, '/');
	if (path_start != NULL) {
		size_t poolname_len = path_start - target;
		poolname = strndup(target, poolname_len);
	} else {
		poolname = target;
	}

	if (cfg == NULL) {
		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);
		}
	}

	(void) asprintf(&bogus_name, "%s%s", poolname, BOGUS_SUFFIX);
	fnvlist_add_string(cfg, ZPOOL_CONFIG_POOL_NAME, bogus_name);

	error = spa_import(bogus_name, cfg, NULL,
	    ZFS_IMPORT_MISSING_LOG | ZFS_IMPORT_CHECKPOINT);
	if (error != 0) {
		fatal("Tried to import pool \"%s\" but spa_import() failed "
		    "with error %d\n", bogus_name, error);
	}

	if (new_path != NULL && path_start != NULL)
		(void) asprintf(new_path, "%s%s", bogus_name, path_start);

	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);
	range_tree_verify(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));
		space_map_update(checkpoint_sm);

		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,
		    verify_checkpoint_sm_entry_cb, &vcsec));
		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];
			ASSERT3P(current_vd->vdev_checkpoint_sm, ==, NULL);
		}
	}

	/* 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.
			 */
			range_tree_walk(ckpoint_msp->ms_allocatable,
			    (range_tree_func_t *)range_tree_verify,
			    current_msp->ms_allocatable);
		}
	}

	/* for cleaner progress output */
	(void) fprintf(stderr, "\n");
}

static void
verify_checkpoint_blocks(spa_t *spa)
{
	spa_t *checkpoint_spa;
	char *checkpoint_pool;
	nvlist_t *config = NULL;
	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, config,
	    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));
		space_map_update(checkpoint_sm);
		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");
		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);
}

/* ARGSUSED */
static void
mos_leaks_cb(void *arg, uint64_t start, uint64_t size)
{
	for (uint64_t i = start; i < size; i++) {
		(void) printf("MOS object %llu referenced but not allocated\n",
		    (u_longlong_t)i);
	}
}

static range_tree_t *mos_refd_objs;

static void
mos_obj_refd(uint64_t obj)
{
	if (obj != 0 && mos_refd_objs != NULL)
		range_tree_add(mos_refd_objs, obj, 1);
}

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_top_zap);
	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));
	}

	for (uint64_t c = 0; c < vd->vdev_children; c++) {
		mos_leak_vdev(vd->vdev_child[c]);
	}
}

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);
	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);

	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);
	}

	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_deadlist(&ds->ds_deadlist);
		dsl_dataset_rele(ds, FTAG);
		dsl_pool_config_exit(dp, FTAG);

		count_ds_mos_objects(dp->dp_origin_snap);
		dump_deadlist(&dp->dp_origin_snap->ds_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 class = 0; class < DDT_CLASSES; class++) {
		for (uint64_t type = 0; type < DDT_TYPES; type++) {
			for (uint64_t cksum = 0;
			    cksum < ZIO_CHECKSUM_FUNCTIONS; cksum++) {
				ddt_t *ddt = spa->spa_ddt[cksum];
				mos_obj_refd(ddt->ddt_object[type][class]);
			}
		}
	}

	/*
	 * 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 (range_tree_contains(mos_refd_objs, object, 1)) {
			range_tree_remove(mos_refd_objs, object, 1);
		} else {
			dmu_object_info_t doi;
			const char *name;
			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) range_tree_walk(mos_refd_objs, mos_leaks_cb, NULL);
	if (!range_tree_is_empty(mos_refd_objs))
		rv = 2;
	range_tree_vacate(mos_refd_objs, NULL, NULL);
	range_tree_destroy(mos_refd_objs);
	return (rv);
}

static void
dump_zpool(spa_t *spa)
{
	dsl_pool_t *dp = spa_get_dsl(spa);
	int rc = 0;

	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['d'] > 2 || dump_opt['m'])
		dump_metaslabs(spa);
	if (dump_opt['M'])
		dump_metaslab_groups(spa);

	if (dump_opt['d'] || dump_opt['i']) {
		mos_refd_objs = range_tree_create(NULL, NULL);
		dump_dir(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);
		}
		(void) dmu_objset_find(spa_name(spa), dump_one_dir,
		    NULL, DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);

		if (rc == 0 && !dump_opt['L'])
			rc = dump_mos_leaks(spa);

		for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
			uint64_t refcount;

			if (!(spa_feature_table[f].fi_flags &
			    ZFEATURE_FLAG_PER_DATASET)) {
				ASSERT0(dataset_feature_count[f]);
				continue;
			}
			(void) feature_get_refcount(spa,
			    &spa_feature_table[f], &refcount);
			if (dataset_feature_count[f] != refcount) {
				(void) printf("%s feature refcount mismatch: "
				    "%lld datasets != %lld refcount\n",
				    spa_feature_table[f].fi_uname,
				    (longlong_t)dataset_feature_count[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();
		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_PHYS		0x0020
#define	ZDB_FLAG_RAW		0x0040
#define	ZDB_FLAG_PRINT_BLKPTR	0x0080

static int flagbits[256];

static void
zdb_print_blkptr(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, int flags)
{
	zdb_dump_indirect((blkptr_t *)buf, SPA_GBH_NBLKPTRS, flags);
}

static void
zdb_dump_block_raw(void *buf, uint64_t size, int flags)
{
	if (flags & ZDB_FLAG_BSWAP)
		byteswap_uint64_array(buf, size);
	(void) write(1, buf, 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);

	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 heirarchy.  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 == '\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);
}

/* ARGSUSED */
static int
random_get_pseudo_bytes_cb(void *buf, size_t len, void *unused)
{
	return (random_get_pseudo_bytes(buf, len));
}

/*
 * Read a block from a pool and print it out.  The syntax of the
 * block descriptor is:
 *
 *	pool:vdev_specifier:offset:size[: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
 *		 p: Do I/O to physical offset
 *		 r: Dump raw data to stdout
 *
 *              * = not yet implemented
 */
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, size = 0, psize = 0, lsize = 0, blkptr_offset = 0;
	zio_t *zio;
	vdev_t *vd;
	abd_t *pabd;
	void *lbuf, *buf;
	const char *s, *vdev;
	char *p, *dup, *flagstr;
	int i, error;

	dup = strdup(thing);
	s = strtok(dup, ":");
	vdev = s ? s : "";
	s = strtok(NULL, ":");
	offset = strtoull(s ? s : "", NULL, 16);
	s = strtok(NULL, ":");
	size = strtoull(s ? s : "", NULL, 16);
	s = strtok(NULL, ":");
	if (s)
		flagstr = strdup(s);
	else
		flagstr = strdup("");

	s = NULL;
	if (size == 0)
		s = "size must not be zero";
	if (!IS_P2ALIGNED(size, DEV_BSIZE))
		s = "size must be a multiple of sector size";
	if (!IS_P2ALIGNED(offset, DEV_BSIZE))
		s = "offset must be a multiple of sector size";
	if (s) {
		(void) printf("Invalid block specifier: %s  - %s\n", thing, s);
		free(flagstr);
		free(dup);
		return;
	}

	for (s = strtok(flagstr, ":"); s; s = strtok(NULL, ":")) {
		for (i = 0; flagstr[i]; i++) {
			int bit = flagbits[(uchar_t)flagstr[i]];

			if (bit == 0) {
				(void) printf("***Invalid flag: %c\n",
				    flagstr[i]);
				continue;
			}
			flags |= bit;

			/* If it's not something with an argument, keep going */
			if ((bit & (ZDB_FLAG_CHECKSUM |
			    ZDB_FLAG_PRINT_BLKPTR)) == 0)
				continue;

			p = &flagstr[i + 1];
			if (bit == ZDB_FLAG_PRINT_BLKPTR)
				blkptr_offset = strtoull(p, &p, 16);
			if (*p != ':' && *p != '\0') {
				(void) printf("***Invalid flag arg: '%s'\n", s);
				free(flagstr);
				free(dup);
				return;
			}
			i += p - &flagstr[i + 1]; /* skip over the number */
		}
	}
	free(flagstr);

	vd = zdb_vdev_lookup(spa->spa_root_vdev, vdev);
	if (vd == NULL) {
		(void) printf("***Invalid vdev: %s\n", vdev);
		free(dup);
		return;
	} 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);
	}

	psize = size;
	lsize = size;

	pabd = abd_alloc_linear(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], !!(flags & ZDB_FLAG_GBH));
	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, 0);

	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_CACHE | ZIO_FLAG_DONT_QUEUE |
		    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;
	}

	if (flags & ZDB_FLAG_DECOMPRESS) {
		/*
		 * We don't know how the data was compressed, so just try
		 * every decompress function at every inflated blocksize.
		 */
		enum zio_compress c;
		void *pbuf2 = umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL);
		void *lbuf2 = umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL);

		abd_copy_to_buf(pbuf2, pabd, psize);

		VERIFY0(abd_iterate_func(pabd, psize, SPA_MAXBLOCKSIZE - psize,
		    random_get_pseudo_bytes_cb, NULL));

		VERIFY0(random_get_pseudo_bytes((uint8_t *)pbuf2 + psize,
		    SPA_MAXBLOCKSIZE - psize));

		for (lsize = SPA_MAXBLOCKSIZE; lsize > psize;
		    lsize -= SPA_MINBLOCKSIZE) {
			for (c = 0; c < ZIO_COMPRESS_FUNCTIONS; c++) {
				if (zio_decompress_data(c, pabd,
				    lbuf, psize, lsize) == 0 &&
				    zio_decompress_data_buf(c, pbuf2,
				    lbuf2, psize, lsize) == 0 &&
				    bcmp(lbuf, lbuf2, lsize) == 0)
					break;
			}
			if (c != ZIO_COMPRESS_FUNCTIONS)
				break;
			lsize -= SPA_MINBLOCKSIZE;
		}

		umem_free(pbuf2, SPA_MAXBLOCKSIZE);
		umem_free(lbuf2, SPA_MAXBLOCKSIZE);

		if (lsize <= psize) {
			(void) printf("Decompress of %s failed\n", thing);
			goto out;
		}
		buf = lbuf;
		size = lsize;
	} else {
		buf = abd_to_buf(pabd);
		size = psize;
	}

	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, size, flags);
	else if (flags & ZDB_FLAG_INDIRECT)
		zdb_dump_indirect((blkptr_t *)buf, size / sizeof (blkptr_t),
		    flags);
	else if (flags & ZDB_FLAG_GBH)
		zdb_dump_gbh(buf, flags);
	else
		zdb_dump_block(thing, buf, size, flags);

out:
	abd_free(pabd);
	umem_free(lbuf, SPA_MAXBLOCKSIZE);
	free(dup);
}

static void
zdb_embedded_block(char *thing)
{
	blkptr_t bp;
	unsigned long long *words = (void *)&bp;
	char *buf;
	int err;

	bzero(&bp, sizeof (bp));
	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");
		exit(1);
	}
	ASSERT3U(BPE_GET_LSIZE(&bp), <=, SPA_MAXBLOCKSIZE);
	buf = malloc(SPA_MAXBLOCKSIZE);
	if (buf == NULL) {
		(void) fprintf(stderr, "out of memory\n");
		exit(1);
	}
	err = decode_embedded_bp(&bp, buf, BPE_GET_LSIZE(&bp));
	if (err != 0) {
		(void) fprintf(stderr, "decode failed: %u\n", err);
		free(buf);
		exit(1);
	}
	zdb_dump_block_raw(buf, BPE_GET_LSIZE(&bp), 0);
	free(buf);
}

static boolean_t
pool_match(nvlist_t *cfg, char *tgt)
{
	uint64_t v, guid = strtoull(tgt, NULL, 0);
	char *s;

	if (guid != 0) {
		if (nvlist_lookup_uint64(cfg, ZPOOL_CONFIG_POOL_GUID, &v) == 0)
			return (v == guid);
	} else {
		if (nvlist_lookup_string(cfg, ZPOOL_CONFIG_POOL_NAME, &s) == 0)
			return (strcmp(s, tgt) == 0);
	}
	return (B_FALSE);
}

static char *
find_zpool(char **target, nvlist_t **configp, int dirc, char **dirv)
{
	nvlist_t *pools;
	nvlist_t *match = NULL;
	char *name = NULL;
	char *sepp = NULL;
	char sep = '\0';
	int count = 0;
	importargs_t args;

	bzero(&args, sizeof (args));
	args.paths = dirc;
	args.path = dirv;
	args.can_be_active = B_TRUE;

	if ((sepp = strpbrk(*target, "/@")) != NULL) {
		sep = *sepp;
		*sepp = '\0';
	}

	pools = zpool_search_import(g_zfs, &args);

	if (pools != NULL) {
		nvpair_t *elem = NULL;
		while ((elem = nvlist_next_nvpair(pools, elem)) != NULL) {
			verify(nvpair_value_nvlist(elem, configp) == 0);
			if (pool_match(*configp, *target)) {
				count++;
				if (match != NULL) {
					/* print previously found config */
					if (name != NULL) {
						(void) printf("%s\n", name);
						dump_nvlist(match, 8);
						name = NULL;
					}
					(void) printf("%s\n",
					    nvpair_name(elem));
					dump_nvlist(*configp, 8);
				} else {
					match = *configp;
					name = nvpair_name(elem);
				}
			}
		}
	}
	if (count > 1)
		(void) fatal("\tMatched %d pools - use pool GUID "
		    "instead of pool name or \n"
		    "\tpool name part of a dataset name to select pool", count);

	if (sepp)
		*sepp = sep;
	/*
	 * If pool GUID was specified for pool id, replace it with pool name
	 */
	if (name && (strstr(*target, name) != *target)) {
		int sz = 1 + strlen(name) + ((sepp) ? strlen(sepp) : 0);

		*target = umem_alloc(sz, UMEM_NOFAIL);
		(void) snprintf(*target, sz, "%s%s", name, sepp ? sepp : "");
	}

	*configp = name ? match : NULL;

	return (name);
}

int
main(int argc, char **argv)
{
	int c;
	struct rlimit rl = { 1024, 1024 };
	spa_t *spa = NULL;
	objset_t *os = NULL;
	int dump_all = 1;
	int verbose = 0;
	int error = 0;
	char **searchdirs = NULL;
	int nsearch = 0;
	char *target;
	nvlist_t *policy = NULL;
	uint64_t max_txg = UINT64_MAX;
	int flags = ZFS_IMPORT_MISSING_LOG;
	int rewind = ZPOOL_NEVER_REWIND;
	char *spa_config_path_env;
	boolean_t target_is_spa = B_TRUE;
	nvlist_t *cfg = NULL;

	(void) setrlimit(RLIMIT_NOFILE, &rl);
	(void) enable_extended_FILE_stdio(-1, -1);

	dprintf_setup(&argc, argv);

	/*
	 * 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;

	while ((c = getopt(argc, argv,
	    "AbcCdDeEFGhiI:klLmMo:Op:PqRsSt:uU:vVx:X")) != -1) {
		switch (c) {
		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 'O':
		case 'R':
		case 's':
		case 'S':
		case 'u':
			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;
		/* NB: Sort single match options below. */
		case 'I':
			max_inflight = strtoull(optarg, NULL, 0);
			if (max_inflight == 0) {
				(void) fprintf(stderr, "maximum number "
				    "of inflight I/Os must be greater "
				    "than 0\n");
				usage();
			}
			break;
		case 'o':
			error = set_global_var(optarg);
			if (error != 0)
				usage();
			break;
		case 'p':
			if (searchdirs == NULL) {
				searchdirs = umem_alloc(sizeof (char *),
				    UMEM_NOFAIL);
			} else {
				char **tmp = umem_alloc((nsearch + 1) *
				    sizeof (char *), UMEM_NOFAIL);
				bcopy(searchdirs, tmp, 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':
			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();
	}

	/*
	 * ZDB does not typically re-read blocks; therefore limit the ARC
	 * to 256 MB, which can be used entirely for metadata.
	 */
	zfs_arc_max = zfs_arc_meta_limit = 256 * 1024 * 1024;

	/*
	 * "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;

	kernel_init(FREAD);
	g_zfs = libzfs_init();
	if (g_zfs == NULL)
		fatal("Fail to initialize zfs");

	if (dump_all)
		verbose = MAX(verbose, 1);

	for (c = 0; c < 256; c++) {
		if (dump_all && strchr("AeEFklLOPRSX", c) == NULL)
			dump_opt[c] = 1;
		if (dump_opt[c])
			dump_opt[c] += verbose;
	}

	aok = (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();

	if (dump_opt['E']) {
		if (argc != 1)
			usage();
		zdb_embedded_block(argv[0]);
		return (0);
	}

	if (argc < 1) {
		if (!dump_opt['e'] && dump_opt['C']) {
			dump_cachefile(spa_config_path);
			return (0);
		}
		usage();
	}

	if (dump_opt['l'])
		return (dump_label(argv[0]));

	if (dump_opt['O']) {
		if (argc != 2)
			usage();
		dump_opt['v'] = verbose + 3;
		return (dump_path(argv[0], argv[1]));
	}

	if (dump_opt['X'] || dump_opt['F'])
		rewind = ZPOOL_DO_REWIND |
		    (dump_opt['X'] ? ZPOOL_EXTREME_REWIND : 0);

	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;
	target = argv[0];

	if (dump_opt['e']) {
		char *name = find_zpool(&target, &cfg, nsearch, searchdirs);

		error = ENOENT;
		if (name) {
			if (dump_opt['C'] > 1) {
				(void) printf("\nConfiguration for import:\n");
				dump_nvlist(cfg, 8);
			}

			if (nvlist_add_nvlist(cfg,
			    ZPOOL_LOAD_POLICY, policy) != 0) {
				fatal("can't open '%s': %s",
				    target, strerror(ENOMEM));
			}
			error = spa_import(name, cfg, NULL, flags);
		}
	}

	char *checkpoint_pool = NULL;
	char *checkpoint_target = NULL;
	if (dump_opt['k']) {
		checkpoint_pool = import_checkpointed_state(target, cfg,
		    &checkpoint_target);

		if (checkpoint_target != NULL)
			target = checkpoint_target;

	}

	if (strpbrk(target, "/@") != NULL) {
		size_t targetlen;

		target_is_spa = B_FALSE;
		/*
		 * Remove any trailing slash.  Later code would get confused
		 * by it, but we want to allow it so that "pool/" can
		 * indicate that we want to dump the topmost filesystem,
		 * rather than the whole pool.
		 */
		targetlen = strlen(target);
		if (targetlen != 0 && target[targetlen - 1] == '/')
			target[targetlen - 1] = '\0';
	}

	if (error == 0) {
		if (dump_opt['k'] && (target_is_spa || dump_opt['R'])) {
			ASSERT(checkpoint_pool != NULL);
			ASSERT(checkpoint_target == NULL);

			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']) {
			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 {
			error = open_objset(target, DMU_OST_ANY, FTAG, &os);
		}
	}
	nvlist_free(policy);

	if (error)
		fatal("can't open '%s': %s", target, strerror(error));

	argv++;
	argc--;
	if (!dump_opt['R']) {
		if (argc > 0) {
			zopt_objects = argc;
			zopt_object = calloc(zopt_objects, sizeof (uint64_t));
			for (unsigned i = 0; i < zopt_objects; i++) {
				errno = 0;
				zopt_object[i] = strtoull(argv[i], NULL, 0);
				if (zopt_object[i] == 0 && errno != 0)
					fatal("bad number %s: %s",
					    argv[i], strerror(errno));
			}
		}
		if (os != NULL) {
			dump_dir(os);
		} else if (zopt_objects > 0 && !dump_opt['m']) {
			dump_dir(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['p'] = ZDB_FLAG_PHYS;
		flagbits['r'] = ZDB_FLAG_RAW;

		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);
	}

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

	fuid_table_destroy();

	dump_debug_buffer();

	libzfs_fini(g_zfs);
	kernel_fini();

	return (error);
}