Remove bcopy(), bzero(), bcmp()

[mirror_zfs.git] / cmd / zdb / zdb.c

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

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <getopt.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/dsl_bookmark.h>
#include <sys/dbuf.h>
#include <sys/zil.h>
#include <sys/zil_impl.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <sys/dmu_send.h>
#include <sys/dmu_traverse.h>
#include <sys/zio_checksum.h>
#include <sys/zio_compress.h>
#include <sys/zfs_fuid.h>
#include <sys/arc.h>
#include <sys/arc_impl.h>
#include <sys/ddt.h>
#include <sys/zfeature.h>
#include <sys/abd.h>
#include <sys/blkptr.h>
#include <sys/dsl_crypt.h>
#include <sys/dsl_scan.h>
#include <sys/btree.h>
#include <zfs_comutil.h>
#include <sys/zstd/zstd.h>

#include <libnvpair.h>
#include <libzutil.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_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)

/* Some platforms require part of inode IDs to be remapped */
#ifdef __APPLE__
#define ZDB_MAP_OBJECT_ID(obj) INO_XNUTOZFS(obj, 2)
#else
#define ZDB_MAP_OBJECT_ID(obj) (obj)
#endif

static char *
zdb_ot_name(dmu_object_type_t type)
{
        if (type < DMU_OT_NUMTYPES)
                return (dmu_ot[type].ot_name);
        else if ((type & DMU_OT_NEWTYPE) &&
            ((type & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS))
                return (dmu_ot_byteswap[type & DMU_OT_BYTESWAP_MASK].ob_name);
        else
                return ("UNKNOWN");
}

extern int reference_tracking_enable;
extern int zfs_recover;
extern unsigned long zfs_arc_meta_min, zfs_arc_meta_limit;
extern int zfs_vdev_async_read_max_active;
extern boolean_t spa_load_verify_dryrun;
extern boolean_t spa_mode_readable_spacemaps;
extern int zfs_reconstruct_indirect_combinations_max;
extern int zfs_btree_verify_intensity;

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

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

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

typedef struct zopt_object_range {
        uint64_t zor_obj_start;
        uint64_t zor_obj_end;
        uint64_t zor_flags;
} zopt_object_range_t;
zopt_object_range_t *zopt_object_ranges = NULL;
static unsigned zopt_object_args = 0;

static int flagbits[256];

#define ZOR_FLAG_PLAIN_FILE     0x0001
#define ZOR_FLAG_DIRECTORY      0x0002
#define ZOR_FLAG_SPACE_MAP      0x0004
#define ZOR_FLAG_ZAP            0x0008
#define ZOR_FLAG_ALL_TYPES      -1
#define ZOR_SUPPORTED_FLAGS     (ZOR_FLAG_PLAIN_FILE    | \
                                ZOR_FLAG_DIRECTORY      | \
                                ZOR_FLAG_SPACE_MAP      | \
                                ZOR_FLAG_ZAP)

#define ZDB_FLAG_CHECKSUM       0x0001
#define ZDB_FLAG_DECOMPRESS     0x0002
#define ZDB_FLAG_BSWAP          0x0004
#define ZDB_FLAG_GBH            0x0008
#define ZDB_FLAG_INDIRECT       0x0010
#define ZDB_FLAG_RAW            0x0020
#define ZDB_FLAG_PRINT_BLKPTR   0x0040
#define ZDB_FLAG_VERBOSE        0x0080

uint64_t max_inflight_bytes = 256 * 1024 * 1024; /* 256MB */
static int leaked_objects = 0;
static range_tree_t *mos_refd_objs;

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

typedef struct sublivelist_verify {
        /* FREE's that haven't yet matched to an ALLOC, in one sub-livelist */
        zfs_btree_t sv_pair;

        /* ALLOC's without a matching FREE, accumulates across sub-livelists */
        zfs_btree_t sv_leftover;
} sublivelist_verify_t;

static int
livelist_compare(const void *larg, const void *rarg)
{
        const blkptr_t *l = larg;
        const blkptr_t *r = rarg;

        /* Sort them according to dva[0] */
        uint64_t l_dva0_vdev, r_dva0_vdev;
        l_dva0_vdev = DVA_GET_VDEV(&l->blk_dva[0]);
        r_dva0_vdev = DVA_GET_VDEV(&r->blk_dva[0]);
        if (l_dva0_vdev < r_dva0_vdev)
                return (-1);
        else if (l_dva0_vdev > r_dva0_vdev)
                return (+1);

        /* if vdevs are equal, sort by offsets. */
        uint64_t l_dva0_offset;
        uint64_t r_dva0_offset;
        l_dva0_offset = DVA_GET_OFFSET(&l->blk_dva[0]);
        r_dva0_offset = DVA_GET_OFFSET(&r->blk_dva[0]);
        if (l_dva0_offset < r_dva0_offset) {
                return (-1);
        } else if (l_dva0_offset > r_dva0_offset) {
                return (+1);
        }

        /*
         * Since we're storing blkptrs without cancelling FREE/ALLOC pairs,
         * it's possible the offsets are equal. In that case, sort by txg
         */
        if (l->blk_birth < r->blk_birth) {
                return (-1);
        } else if (l->blk_birth > r->blk_birth) {
                return (+1);
        }
        return (0);
}

typedef struct sublivelist_verify_block {
        dva_t svb_dva;

        /*
         * We need this to check if the block marked as allocated
         * in the livelist was freed (and potentially reallocated)
         * in the metaslab spacemaps at a later TXG.
         */
        uint64_t svb_allocated_txg;
} sublivelist_verify_block_t;

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

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

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

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

static int
sublivelist_verify_blkptr(void *arg, const blkptr_t *bp, boolean_t free,
    dmu_tx_t *tx)
{
        ASSERT3P(tx, ==, NULL);
        struct sublivelist_verify *sv = arg;
        sublivelist_verify_block_refcnt_t current = {
                        .svbr_blk = *bp,

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

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

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

        return (0);
}

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

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

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

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

        return (err);
}

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

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

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

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

        return (0);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        vdev_t *vd = vdev_lookup_top(spa, vdev_id);

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

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

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

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                if (!vdev_is_concrete(vd))
                        continue;

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

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

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

                        mv_populate_livelist_allocs(&mv, &sv);

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

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

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

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

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

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

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

        (void) fprintf(stderr, "    Dataset name must include at least one "
            "separator character '/' or '@'\n");
        (void) fprintf(stderr, "    If dataset name is specified, only that "
            "dataset is dumped\n");
        (void) fprintf(stderr,  "    If object numbers or object number "
            "ranges are specified, only those\n"
            "    objects or ranges are dumped.\n\n");
        (void) fprintf(stderr,
            "    Object ranges take the form <start>:<end>[:<flags>]\n"
            "        start    Starting object number\n"
            "        end      Ending object number, or -1 for no upper bound\n"
            "        flags    Optional flags to select object types:\n"
            "            A     All objects (this is the default)\n"
            "            d     ZFS directories\n"
            "            f     ZFS files \n"
            "            m     SPA space maps\n"
            "            z     ZAPs\n"
            "            -     Negate effect of next flag\n\n");
        (void) fprintf(stderr, "    Options to control amount of output:\n");
        (void) fprintf(stderr, "        -b --block-stats             "
            "block statistics\n");
        (void) fprintf(stderr, "        -c --checksum                "
            "checksum all metadata (twice for all data) blocks\n");
        (void) fprintf(stderr, "        -C --config                  "
            "config (or cachefile if alone)\n");
        (void) fprintf(stderr, "        -d --datasets                "
            "dataset(s)\n");
        (void) fprintf(stderr, "        -D --dedup-stats             "
            "dedup statistics\n");
        (void) fprintf(stderr, "        -E --embedded-block-pointer=INTEGER\n"
            "                                     decode and display block "
            "from an embedded block pointer\n");
        (void) fprintf(stderr, "        -h --history                 "
            "pool history\n");
        (void) fprintf(stderr, "        -i --intent-logs             "
            "intent logs\n");
        (void) fprintf(stderr, "        -l --label                   "
            "read label contents\n");
        (void) fprintf(stderr, "        -k --checkpointed-state      "
            "examine the checkpointed state of the pool\n");
        (void) fprintf(stderr, "        -L --disable-leak-tracking   "
            "disable leak tracking (do not load spacemaps)\n");
        (void) fprintf(stderr, "        -m --metaslabs               "
            "metaslabs\n");
        (void) fprintf(stderr, "        -M --metaslab-groups         "
            "metaslab groups\n");
        (void) fprintf(stderr, "        -O --object-lookups          "
            "perform object lookups by path\n");
        (void) fprintf(stderr, "        -r --copy-object             "
            "copy an object by path to file\n");
        (void) fprintf(stderr, "        -R --read-block              "
            "read and display block from a device\n");
        (void) fprintf(stderr, "        -s --io-stats                "
            "report stats on zdb's I/O\n");
        (void) fprintf(stderr, "        -S --simulate-dedup          "
            "simulate dedup to measure effect\n");
        (void) fprintf(stderr, "        -v --verbose                 "
            "verbose (applies to all others)\n");
        (void) fprintf(stderr, "        -y --livelist                "
            "perform livelist and metaslab validation on any livelists being "
            "deleted\n\n");
        (void) fprintf(stderr, "    Below options are intended for use "
            "with other options:\n");
        (void) fprintf(stderr, "        -A --ignore-assertions       "
            "ignore assertions (-A), enable panic recovery (-AA) or both "
            "(-AAA)\n");
        (void) fprintf(stderr, "        -e --exported                "
            "pool is exported/destroyed/has altroot/not in a cachefile\n");
        (void) fprintf(stderr, "        -F --automatic-rewind        "
            "attempt automatic rewind within safe range of transaction "
            "groups\n");
        (void) fprintf(stderr, "        -G --dump-debug-msg          "
            "dump zfs_dbgmsg buffer before exiting\n");
        (void) fprintf(stderr, "        -I --inflight=INTEGER        "
            "specify the maximum number of checksumming I/Os "
            "[default is 200]\n");
        (void) fprintf(stderr, "        -o --option=\"OPTION=INTEGER\" "
            "set global variable to an unsigned 32-bit integer\n");
        (void) fprintf(stderr, "        -p --path==PATH              "
            "use one or more with -e to specify path to vdev dir\n");
        (void) fprintf(stderr, "        -P --parseable               "
            "print numbers in parseable form\n");
        (void) fprintf(stderr, "        -q --skip-label              "
            "don't print label contents\n");
        (void) fprintf(stderr, "        -t --txg=INTEGER             "
            "highest txg to use when searching for uberblocks\n");
        (void) fprintf(stderr, "        -u --uberblock               "
            "uberblock\n");
        (void) fprintf(stderr, "        -U --cachefile=PATH          "
            "use alternate cachefile\n");
        (void) fprintf(stderr, "        -V --verbatim                "
            "do verbatim import\n");
        (void) fprintf(stderr, "        -x --dump-blocks=PATH        "
            "dump all read blocks into specified directory\n");
        (void) fprintf(stderr, "        -X --extreme-rewind          "
            "attempt extreme rewind (does not work with dataset)\n");
        (void) fprintf(stderr, "        -Y --all-reconstruction      "
            "attempt all reconstruction combinations for split blocks\n");
        (void) fprintf(stderr, "        -Z --zstd-headers            "
            "show ZSTD headers \n");
        (void) fprintf(stderr, "Specify an option more than once (e.g. -bb) "
            "to make only that option verbose\n");
        (void) fprintf(stderr, "Default is to dump everything non-verbosely\n");
        exit(1);
}

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

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

        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);
}

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

        if (shp == NULL)
                return;

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

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

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

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

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

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

        if (data == NULL) {
                dmu_object_info_t doi;

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

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

        if (size == 0) {
                (void) printf("\t\t[]\n");
                return;
        }

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

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

static void
dump_zap(objset_t *os, uint64_t object, void *data, size_t size)
{
        (void) data, (void) size;
        zap_cursor_t zc;
        zap_attribute_t 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) {
                        if (strcmp(attr.za_name,
                            DSL_CRYPTO_KEY_MASTER_KEY) == 0 ||
                            strcmp(attr.za_name,
                            DSL_CRYPTO_KEY_HMAC_KEY) == 0 ||
                            strcmp(attr.za_name, DSL_CRYPTO_KEY_IV) == 0 ||
                            strcmp(attr.za_name, DSL_CRYPTO_KEY_MAC) == 0 ||
                            strcmp(attr.za_name, DMU_POOL_CHECKSUM_SALT) == 0) {
                                uint8_t *u8 = prop;

                                for (i = 0; i < attr.za_num_integers; i++) {
                                        (void) printf("%02x", u8[i]);
                                }
                        } else {
                                (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;
        uint64_t i;
        char bytes[32], comp[32], uncomp[32];

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

        if (bpop == NULL)
                return;

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

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

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

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

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

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

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

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

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

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

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

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

static void
dump_sa_layouts(objset_t *os, uint64_t object, void *data, size_t size)
{
        (void) data, (void) size;
        zap_cursor_t zc;
        zap_attribute_t 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);
}

static void
dump_zpldir(objset_t *os, uint64_t object, void *data, size_t size)
{
        (void) data, (void) size;
        zap_cursor_t zc;
        zap_attribute_t 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)
{
        uint64_t obsolete_sm_object;
        int refcount = 0;

        VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
        if (vd->vdev_top == vd && obsolete_sm_object != 0) {
                dmu_object_info_t doi;
                VERIFY0(dmu_object_info(vd->vdev_spa->spa_meta_objset,
                    obsolete_sm_object, &doi));
                if (doi.doi_bonus_size == sizeof (space_map_phys_t)) {
                        refcount++;
                }
        } else {
                ASSERT3P(vd->vdev_obsolete_sm, ==, NULL);
                ASSERT3U(obsolete_sm_object, ==, 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
get_log_spacemap_refcount(spa_t *spa)
{
        return (avl_numnodes(&spa->spa_sm_logs_by_txg));
}

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

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

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

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

        if (sm == NULL)
                return;

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

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

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

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

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

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

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

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

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

        (void) printf("\t %25s %10lu   %7s  %6s   %4s %4d%%\n",
            "segments", zfs_btree_numnodes(t), "maxsize", maxbuf,
            "freepct", free_pct);
        (void) printf("\tIn-memory histogram:\n");
        dump_histogram(rt->rt_histogram, 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);
                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 (vd->vdev_ops == &vdev_draid_ops)
                ASSERT3U(msp->ms_size, <=, 1ULL << vd->vdev_ms_shift);
        else
                ASSERT3U(msp->ms_size, ==, 1ULL << vd->vdev_ms_shift);

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

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

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

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

        (void) printf("\tvdev %10llu   %s",
            (u_longlong_t)vd->vdev_id, bias_str);

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

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

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

        metaslab_class_histogram_verify(mc);

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

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

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

                (void) printf("\tvdev %10llu\t\tmetaslabs%5llu\t\t"
                    "fragmentation",
                    (u_longlong_t)tvd->vdev_id,
                    (u_longlong_t)tvd->vdev_ms_count);
                if (mg->mg_fragmentation == ZFS_FRAG_INVALID) {
                        (void) printf("%3s\n", "-");
                } else {
                        (void) printf("%3llu%%\n",
                            (u_longlong_t)mg->mg_fragmentation);
                }
                dump_histogram(mg->mg_histogram, 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;
        VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
        if (obsolete_sm_object != 0) {
                objset_t *mos = vd->vdev_spa->spa_meta_objset;
                (void) printf("obsolete space map object %llu:\n",
                    (u_longlong_t)obsolete_sm_object);
                ASSERT(vd->vdev_obsolete_sm != NULL);
                ASSERT3U(space_map_object(vd->vdev_obsolete_sm), ==,
                    obsolete_sm_object);
                dump_spacemap(mos, vd->vdev_obsolete_sm);
                (void) printf("\n");
        }
}

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

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

        if (!dump_opt['d'] && zopt_metaslab_args > 0) {
                c = zopt_metaslab[0];

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

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

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

                print_vdev_indirect(vd);

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

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

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

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

static void
dump_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;
        int p;

        for (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 = {{{0}}};
        ddt_stat_t dds_total = {0};

        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);
}

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

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

        do {
                len = SPA_OLD_MAXBLOCKSIZE;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        ASSERT(zb->zb_level >= 0);

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

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

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

        if (BP_IS_HOLE(bp))
                return;

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

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

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

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

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

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

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

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

        blkbuf[0] = '\0';

        for (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));
                if (bp_freed)
                        (void) snprintf(blkbuf + strlen(blkbuf),
                            buflen - strlen(blkbuf), " %s", "FREE");
                (void) snprintf(blkbuf + strlen(blkbuf),
                    buflen - strlen(blkbuf), " cksum=%llx:%llx:%llx:%llx",
                    (u_longlong_t)bp->blk_cksum.zc_word[0],
                    (u_longlong_t)bp->blk_cksum.zc_word[1],
                    (u_longlong_t)bp->blk_cksum.zc_word[2],
                    (u_longlong_t)bp->blk_cksum.zc_word[3]);
        }
}

static void
print_indirect(spa_t *spa, 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, B_FALSE);
        if (dump_opt['Z'] && BP_GET_COMPRESS(bp) == ZIO_COMPRESS_ZSTD)
                snprintf_zstd_header(spa, 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(spa, bp, zb, dnp);

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

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

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

                        SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
                            zb->zb_level - 1,
                            zb->zb_blkid * epb + i);
                        err = visit_indirect(spa, dnp, cbp, &czb);
                        if (err)
                                break;
                        fill += BP_GET_FILL(cbp);
                }
                if (!err)
                        ASSERT3U(fill, ==, BP_GET_FILL(bp));
                arc_buf_destroy(buf, &buf);
        }

        return (err);
}

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

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

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

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

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

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

        if (dd == NULL)
                return;

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

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

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

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

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

        if (ds == NULL)
                return;

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

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

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

        if (bp->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 */
        _Static_assert(sizeof (bytes) >= NN_NUMBUF_SZ, "bytes truncated");

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

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

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

        (void) printf("\n");

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

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

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

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

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

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

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

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

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


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

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

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

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

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

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

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

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

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

        redact_block_phys_t *rbp_buf;
        uint64_t size;
        dmu_object_info_t doi;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        (void) printf("\n");

        dsl_deadlist_iterate(dl, dsl_deadlist_entry_dump, NULL);
}

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

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

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

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

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

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

        VERIFY3P(sa_os, ==, NULL);
        /*
         * We can't own an objset if it's redacted.  Therefore, we do this
         * dance: hold the objset, then acquire a long hold on its dataset, then
         * release the pool (which is held as part of holding the objset).
         */
        err = dmu_objset_hold(path, tag, osp);
        if (err != 0) {
                (void) fprintf(stderr, "failed to hold dataset '%s': %s\n",
                    path, strerror(err));
                return (err);
        }
        dsl_dataset_long_hold(dmu_objset_ds(*osp), tag);
        dsl_pool_rele(dmu_objset_pool(*osp), tag);

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

static void
fuid_table_destroy(void)
{
        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");
}

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

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

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

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

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

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

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

                (void) printf("\t\t%s = ", nvpair_name(elem));
                nvpair_value_byte_array(elem, &value, &cnt);
                for (idx = 0; idx < cnt; ++idx) {
                        if (isprint(value[idx]))
                                (void) putchar(value[idx]);
                        else
                                (void) printf("\\%3.3o", value[idx]);
                }
                (void) putchar('\n');
        }

        nvlist_free(sa_xattr);
        free(sa_xattr_packed);
}

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

        error = sa_size(hdl, sa_attr_table[ZPL_SYMLINK], &sa_symlink_size);
        if (error || sa_symlink_size == 0) {
                return;
        }
        if (sa_lookup(hdl, sa_attr_table[ZPL_SYMLINK],
            &linktarget, sa_symlink_size) == 0)
                (void) printf("\ttarget %s\n", linktarget);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                break;
        }

        return (match);
}

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

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

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

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

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

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

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

        zdb_nicenum(doi.doi_metadata_block_size, iblk, sizeof (iblk));
        zdb_nicenum(doi.doi_data_block_size, dblk, sizeof (dblk));
        zdb_nicenum(doi.doi_max_offset, lsize, sizeof (lsize));
        zdb_nicenum(doi.doi_physical_blocks_512 << 9, asize, sizeof (asize));
        zdb_nicenum(doi.doi_bonus_size, bonus_size, sizeof (bonus_size));
        zdb_nicenum(doi.doi_dnodesize, dnsize, sizeof (dnsize));
        (void) 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) - strlen(aux),
                    " (K=%s)", ZDB_CHECKSUM_NAME(doi.doi_checksum));
        }

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

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

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

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

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

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

                *print_header = B_TRUE;
        }

        if (verbosity >= 5)
                dump_indirect(dn);

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        print_header = B_TRUE;

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

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

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

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

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

        dmu_objset_name(os, osname);

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

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

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

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

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

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

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

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

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

        if (verbosity < 2)
                return;

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

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

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

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

        (void) printf("\n");

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

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

        ASSERT3U(object_count, ==, usedobjs);

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

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

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

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

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

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


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

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

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

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

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

        if (fstat64(fd, &statbuf) != 0) {
                (void) printf("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);
}

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

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

        stats->zns_list_count++;

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

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

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

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

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

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

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

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

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

        collect_nvlist_stats(nvl, &stats);

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

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

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

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

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

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

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

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

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

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

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

        return (difference);
}

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

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

        return (rec);
}

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

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

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

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

        return (rec);
}

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

        return (-1);
}

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

#define MAX_UBERBLOCK_COUNT (VDEV_UBERBLOCK_RING >> UBERBLOCK_SHIFT)

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

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

        if (dump_opt['q'])
                return;

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

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

        label->header_printed = B_TRUE;
}

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

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

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

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

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

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

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

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

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

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

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

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

                switch (L2BLK_GET_COMPRESS((&lbps[0])->lbp_prop)) {
                case ZIO_COMPRESS_OFF:
                        break;
                default:
                        abd = abd_alloc_for_io(asize, B_TRUE);
                        abd_copy_from_buf_off(abd, &this_lb, 0, asize);
                        zio_decompress_data(L2BLK_GET_COMPRESS(
                            (&lbps[0])->lbp_prop), abd, &this_lb,
                            asize, sizeof (this_lb), NULL);
                        abd_free(abd);
                        break;
                }

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

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

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

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

                lbps[0] = lbps[1];
                lbps[1] = this_lb.lb_prev_lbp;
        }

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

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

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

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

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

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

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

        return (0);
}

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

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

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

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

#define ZDB_MAX_UB_HEADER_SIZE 32

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

        vdev_t vd;
        char header[ZDB_MAX_UB_HEADER_SIZE];

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

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

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

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

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

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

static char curpath[PATH_MAX];

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

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

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

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

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

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

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

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

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

        return (EINVAL);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

                offset += readsize;
        }

        (void) close(fd);

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

        return (err);
}

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

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

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

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

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

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

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

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

        return (B_FALSE);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                        if (uberblock_verify(ub))
                                continue;

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

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

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

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

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

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

                nvlist_free(label->config_nv);
        }

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

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

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

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

        (void) close(fd);

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

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

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

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

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

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

        for (dsl_bookmark_node_t *dbn =
            avl_first(&dmu_objset_ds(os)->ds_bookmarks); dbn != NULL;
            dbn = AVL_NEXT(&dmu_objset_ds(os)->ds_bookmarks, dbn)) {
                mos_obj_refd(dbn->dbn_phys.zbm_redaction_obj);
                if (dbn->dbn_phys.zbm_redaction_obj != 0)
                        global_feature_count[SPA_FEATURE_REDACTION_BOOKMARKS]++;
                if (dbn->dbn_phys.zbm_flags & ZBM_FLAG_HAS_FBN)
                        global_feature_count[SPA_FEATURE_BOOKMARK_WRITTEN]++;
        }

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

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

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

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

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

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

typedef struct zdb_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_psize_count[SPA_MAX_FOR_16M];
        uint64_t        zcb_lsize_count[SPA_MAX_FOR_16M];
        uint64_t        zcb_asize_count[SPA_MAX_FOR_16M];
        uint64_t        zcb_psize_len[SPA_MAX_FOR_16M];
        uint64_t        zcb_lsize_len[SPA_MAX_FOR_16M];
        uint64_t        zcb_asize_len[SPA_MAX_FOR_16M];
        uint64_t        zcb_psize_total;
        uint64_t        zcb_lsize_total;
        uint64_t        zcb_asize_total;
        uint64_t        zcb_embedded_blocks[NUM_BP_EMBEDDED_TYPES];
        uint64_t        zcb_embedded_histogram[NUM_BP_EMBEDDED_TYPES]
            [BPE_PAYLOAD_SIZE + 1];
        uint64_t        zcb_start;
        hrtime_t        zcb_lastprint;
        uint64_t        zcb_totalasize;
        uint64_t        zcb_errors[256];
        int             zcb_readfails;
        int             zcb_haderrors;
        spa_t           *zcb_spa;
        uint32_t        **zcb_vd_obsolete_counts;
} zdb_cb_t;

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

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

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

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

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

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

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

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

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

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


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

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

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

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

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

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

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

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

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

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

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

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

        ASSERT(type < ZDB_OT_TOTAL);

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

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

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

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

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

                zb->zb_gangs += BP_COUNT_GANG(bp);

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

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

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

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

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

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

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

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

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

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

        if (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);
}

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

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

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

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

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

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

        abd_free(zio->io_abd);
}

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

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

        if (dump_opt['b'] >= 5 && bp->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) || BP_IS_REDACTED(bp))
                return (0);

        type = BP_GET_TYPE(bp);

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

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

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

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

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

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

        zcb->zcb_readfails = 0;

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

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

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

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

                zcb->zcb_lastprint = now;
        }

        return (0);
}

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

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

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

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

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

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

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

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

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

        return (0);
}

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

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

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

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

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

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

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

        spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);

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

        ASSERT0(range_tree_space(svr->svr_allocd_segs));

        range_tree_t *allocs = range_tree_create(NULL, RANGE_SEG64, NULL, 0, 0);
        for (uint64_t msi = 0; msi < vd->vdev_ms_count; msi++) {
                metaslab_t *msp = vd->vdev_ms[msi];

                ASSERT0(range_tree_space(allocs));
                if (msp->ms_sm != NULL)
                        VERIFY0(space_map_load(msp->ms_sm, allocs, SM_ALLOC));
                range_tree_vacate(allocs, range_tree_add, svr->svr_allocd_segs);
        }
        range_tree_destroy(allocs);

        iterate_through_spacemap_logs(spa, load_unflushed_svr_segs_cb, svr);

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

        zcb->zcb_removing_size += 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);
}

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

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

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

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

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

        return (0);
}

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

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

static void
zdb_ddt_leak_init(spa_t *spa, zdb_cb_t *zcb)
{
        ddt_bookmark_t ddb = {0};
        ddt_entry_t dde;
        int error;
        int p;

        ASSERT(!dump_opt['L']);

        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 (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++;
                        }
                }
                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);
}

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));

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

        zcb->zcb_checkpoint_size += cseea.cseea_checkpoint_size;
}

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

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

static int
count_unflushed_space_cb(spa_t *spa, space_map_entry_t *sme,
    uint64_t txg, void *arg)
{
        int64_t *ualloc_space = arg;

        uint64_t offset = sme->sme_offset;
        uint64_t vdev_id = sme->sme_vdev;

        vdev_t *vd = vdev_lookup_top(spa, vdev_id);
        if (!vdev_is_concrete(vd))
                return (0);

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

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

        if (sme->sme_type == SM_ALLOC)
                *ualloc_space += sme->sme_run;
        else
                *ualloc_space -= sme->sme_run;

        return (0);
}

static int64_t
get_unflushed_alloc_space(spa_t *spa)
{
        if (dump_opt['L'])
                return (0);

        int64_t ualloc_space = 0;
        iterate_through_spacemap_logs(spa, count_unflushed_space_cb,
            &ualloc_space);
        return (ualloc_space);
}

static int
load_unflushed_cb(spa_t *spa, space_map_entry_t *sme, uint64_t txg, void *arg)
{
        maptype_t *uic_maptype = arg;

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

        vdev_t *vd = vdev_lookup_top(spa, vdev_id);

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

        metaslab_t *ms = vd->vdev_ms[offset >> vd->vdev_ms_shift];

        ASSERT(sme->sme_type == SM_ALLOC || sme->sme_type == SM_FREE);
        ASSERT(*uic_maptype == SM_ALLOC || *uic_maptype == SM_FREE);

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

        if (*uic_maptype == sme->sme_type)
                range_tree_add(ms->ms_allocatable, offset, size);
        else
                range_tree_remove(ms->ms_allocatable, offset, size);

        return (0);
}

static void
load_unflushed_to_ms_allocatables(spa_t *spa, maptype_t maptype)
{
        iterate_through_spacemap_logs(spa, load_unflushed_cb, &maptype);
}

static void
load_concrete_ms_allocatable_trees(spa_t *spa, maptype_t maptype)
{
        vdev_t *rvd = spa->spa_root_vdev;
        for (uint64_t i = 0; i < rvd->vdev_children; i++) {
                vdev_t *vd = rvd->vdev_child[i];

                ASSERT3U(i, ==, vd->vdev_id);

                if (vd->vdev_ops == &vdev_indirect_ops)
                        continue;

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

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

                        mutex_enter(&msp->ms_lock);
                        range_tree_vacate(msp->ms_allocatable, NULL, NULL);

                        /*
                         * We don't want to spend the CPU manipulating the
                         * size-ordered tree, so clear the range_tree ops.
                         */
                        msp->ms_allocatable->rt_ops = NULL;

                        if (msp->ms_sm != NULL) {
                                VERIFY0(space_map_load(msp->ms_sm,
                                    msp->ms_allocatable, maptype));
                        }
                        if (!msp->ms_loaded)
                                msp->ms_loaded = B_TRUE;
                        mutex_exit(&msp->ms_lock);
                }
        }

        load_unflushed_to_ms_allocatables(spa, maptype);
}

/*
 * vm_idxp is an in-out parameter which (for indirect vdevs) is the
 * index in vim_entries that has the first entry in this metaslab.
 * On return, it will be set to the first entry after this metaslab.
 */
static void
load_indirect_ms_allocatable_tree(vdev_t *vd, metaslab_t *msp,
    uint64_t *vim_idxp)
{
        vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;

        mutex_enter(&msp->ms_lock);
        range_tree_vacate(msp->ms_allocatable, NULL, NULL);

        /*
         * We don't want to spend the CPU manipulating the
         * size-ordered tree, so clear the range_tree ops.
         */
        msp->ms_allocatable->rt_ops = NULL;

        for (; *vim_idxp < vdev_indirect_mapping_num_entries(vim);
            (*vim_idxp)++) {
                vdev_indirect_mapping_entry_phys_t *vimep =
                    &vim->vim_entries[*vim_idxp];
                uint64_t ent_offset = DVA_MAPPING_GET_SRC_OFFSET(vimep);
                uint64_t ent_len = DVA_GET_ASIZE(&vimep->vimep_dst);
                ASSERT3U(ent_offset, >=, msp->ms_start);
                if (ent_offset >= msp->ms_start + msp->ms_size)
                        break;

                /*
                 * Mappings do not cross metaslab boundaries,
                 * because we create them by walking the metaslabs.
                 */
                ASSERT3U(ent_offset + ent_len, <=,
                    msp->ms_start + msp->ms_size);
                range_tree_add(msp->ms_allocatable, ent_offset, ent_len);
        }

        if (!msp->ms_loaded)
                msp->ms_loaded = B_TRUE;
        mutex_exit(&msp->ms_lock);
}

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

        vdev_t *rvd = spa->spa_root_vdev;
        for (uint64_t c = 0; c < rvd->vdev_children; c++) {
                vdev_t *vd = rvd->vdev_child[c];

                ASSERT3U(c, ==, vd->vdev_id);

                if (vd->vdev_ops != &vdev_indirect_ops)
                        continue;

                /*
                 * Note: we don't check for mapping leaks on
                 * removing vdevs because their ms_allocatable's
                 * are used to look for leaks in allocated space.
                 */
                zcb->zcb_vd_obsolete_counts[c] = zdb_load_obsolete_counts(vd);

                /*
                 * Normally, indirect vdevs don't have any
                 * metaslabs.  We want to set them up for
                 * zio_claim().
                 */
                vdev_metaslab_group_create(vd);
                VERIFY0(vdev_metaslab_init(vd, 0));

                vdev_indirect_mapping_t *vim __maybe_unused =
                    vd->vdev_indirect_mapping;
                uint64_t vim_idx = 0;
                for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {

                        (void) fprintf(stderr,
                            "\rloading indirect vdev %llu, "
                            "metaslab %llu of %llu ...",
                            (longlong_t)vd->vdev_id,
                            (longlong_t)vd->vdev_ms[m]->ms_id,
                            (longlong_t)vd->vdev_ms_count);

                        load_indirect_ms_allocatable_tree(vd, vd->vdev_ms[m],
                            &vim_idx);
                }
                ASSERT3U(vim_idx, ==, vdev_indirect_mapping_num_entries(vim));
        }
}

static void
zdb_leak_init(spa_t *spa, zdb_cb_t *zcb)
{
        zcb->zcb_spa = spa;

        if (dump_opt['L'])
                return;

        dsl_pool_t *dp = spa->spa_dsl_pool;
        vdev_t *rvd = spa->spa_root_vdev;

        /*
         * We are going to be changing the meaning of the metaslab's
         * ms_allocatable.  Ensure that the allocator doesn't try to
         * use the tree.
         */
        spa->spa_normal_class->mc_ops = &zdb_metaslab_ops;
        spa->spa_log_class->mc_ops = &zdb_metaslab_ops;
        spa->spa_embedded_log_class->mc_ops = &zdb_metaslab_ops;

        zcb->zcb_vd_obsolete_counts =
            umem_zalloc(rvd->vdev_children * sizeof (uint32_t *),
            UMEM_NOFAIL);

        /*
         * For leak detection, we overload the ms_allocatable trees
         * to contain allocated segments instead of free segments.
         * As a result, we can't use the normal metaslab_load/unload
         * interfaces.
         */
        zdb_leak_init_prepare_indirect_vdevs(spa, zcb);
        load_concrete_ms_allocatable_trees(spa, SM_ALLOC);

        /*
         * On load_concrete_ms_allocatable_trees() we loaded all the
         * allocated entries from the ms_sm to the ms_allocatable for
         * each metaslab. If the pool has a checkpoint or is in the
         * middle of discarding a checkpoint, some of these blocks
         * may have been freed but their ms_sm may not have been
         * updated because they are referenced by the checkpoint. In
         * order to avoid false-positives during leak-detection, we
         * go through the vdev's checkpoint space map and exclude all
         * its entries from their relevant ms_allocatable.
         *
         * We also aggregate the space held by the checkpoint and add
         * it to zcb_checkpoint_size.
         *
         * Note that at this point we are also verifying that all the
         * entries on the checkpoint_sm are marked as allocated in
         * the ms_sm of their relevant metaslab.
         * [see comment in checkpoint_sm_exclude_entry_cb()]
         */
        zdb_leak_init_exclude_checkpoint(spa, zcb);
        ASSERT3U(zcb->zcb_checkpoint_size, ==, spa_get_checkpoint_space(spa));

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

        if (bpobj_is_open(&dp->dp_obsolete_bpobj)) {
                ASSERT(spa_feature_is_enabled(spa,
                    SPA_FEATURE_DEVICE_REMOVAL));
                (void) bpobj_iterate_nofree(&dp->dp_obsolete_bpobj,
                    increment_indirect_mapping_cb, zcb, NULL);
        }

        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;
        boolean_t are_precise = B_FALSE;

        ASSERT(vim != NULL);

        for (uint64_t i = 0; i < vdev_indirect_mapping_num_entries(vim); i++) {
                vdev_indirect_mapping_entry_phys_t *vimep =
                    &vim->vim_entries[i];
                uint64_t obsolete_bytes = 0;
                uint64_t offset = DVA_MAPPING_GET_SRC_OFFSET(vimep);
                metaslab_t *msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];

                /*
                 * This is not very efficient but it's easy to
                 * verify correctness.
                 */
                for (uint64_t inner_offset = 0;
                    inner_offset < DVA_GET_ASIZE(&vimep->vimep_dst);
                    inner_offset += 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]);

                VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise));
                if (bytes_leaked != 0 && (are_precise || dump_opt['d'] >= 5)) {
                        (void) printf("obsolete indirect mapping count "
                            "mismatch on %llu:%llx:%llx : %llx bytes leaked\n",
                            (u_longlong_t)vd->vdev_id,
                            (u_longlong_t)DVA_MAPPING_GET_SRC_OFFSET(vimep),
                            (u_longlong_t)DVA_GET_ASIZE(&vimep->vimep_dst),
                            (u_longlong_t)bytes_leaked);
                }
                total_leaked += ABS(bytes_leaked);
        }

        VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise));
        if (!are_precise && total_leaked > 0) {
                int pct_leaked = total_leaked * 100 /
                    vdev_indirect_mapping_bytes_mapped(vim);
                (void) printf("cannot verify obsolete indirect mapping "
                    "counts of vdev %llu because precise feature was not "
                    "enabled when it was removed: %d%% (%llx bytes) of mapping"
                    "unreferenced\n",
                    (u_longlong_t)vd->vdev_id, pct_leaked,
                    (u_longlong_t)total_leaked);
        } else if (total_leaked > 0) {
                (void) printf("obsolete indirect mapping count mismatch "
                    "for vdev %llu -- %llx total bytes mismatched\n",
                    (u_longlong_t)vd->vdev_id,
                    (u_longlong_t)total_leaked);
                leaks |= B_TRUE;
        }

        vdev_indirect_mapping_free_obsolete_counts(vim,
            zcb->zcb_vd_obsolete_counts[vd->vdev_id]);
        zcb->zcb_vd_obsolete_counts[vd->vdev_id] = NULL;

        return (leaks);
}

static boolean_t
zdb_leak_fini(spa_t *spa, zdb_cb_t *zcb)
{
        if (dump_opt['L'])
                return (B_FALSE);

        boolean_t leaks = B_FALSE;
        vdev_t *rvd = spa->spa_root_vdev;
        for (unsigned c = 0; c < rvd->vdev_children; c++) {
                vdev_t *vd = rvd->vdev_child[c];

                if (zcb->zcb_vd_obsolete_counts[c] != NULL) {
                        leaks |= zdb_check_for_obsolete_leaks(vd, zcb);
                }

                for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {
                        metaslab_t *msp = vd->vdev_ms[m];
                        ASSERT3P(msp->ms_group, ==, (msp->ms_group->mg_class ==
                            spa_embedded_log_class(spa)) ?
                            vd->vdev_log_mg : vd->vdev_mg);

                        /*
                         * ms_allocatable has been overloaded
                         * to contain allocated segments. Now that
                         * we finished traversing all blocks, any
                         * block that remains in the ms_allocatable
                         * represents an allocated block that we
                         * did not claim during the traversal.
                         * Claimed blocks would have been removed
                         * from the ms_allocatable.  For indirect
                         * vdevs, space remaining in the tree
                         * represents parts of the mapping that are
                         * not referenced, which is not a bug.
                         */
                        if (vd->vdev_ops == &vdev_indirect_ops) {
                                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);
}

static int
count_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
{
        (void) tx;
        zdb_cb_t *zcb = arg;

        if (dump_opt['b'] >= 5) {
                char blkbuf[BP_SPRINTF_LEN];
                snprintf_blkptr(blkbuf, sizeof (blkbuf), bp);
                (void) printf("[%s] %s\n",
                    "deferred free", blkbuf);
        }
        zdb_count_block(zcb, NULL, bp, ZDB_OT_DEFERRED);
        return (0);
}

/*
 * Iterate over livelists which have been destroyed by the user but
 * are still present in the MOS, waiting to be freed
 */
static void
iterate_deleted_livelists(spa_t *spa, ll_iter_t func, void *arg)
{
        objset_t *mos = spa->spa_meta_objset;
        uint64_t zap_obj;
        int err = zap_lookup(mos, DMU_POOL_DIRECTORY_OBJECT,
            DMU_POOL_DELETED_CLONES, sizeof (uint64_t), 1, &zap_obj);
        if (err == ENOENT)
                return;
        ASSERT0(err);

        zap_cursor_t zc;
        zap_attribute_t attr;
        dsl_deadlist_t ll;
        /* NULL out os prior to dsl_deadlist_open in case it's garbage */
        ll.dl_os = NULL;
        for (zap_cursor_init(&zc, mos, zap_obj);
            zap_cursor_retrieve(&zc, &attr) == 0;
            (void) zap_cursor_advance(&zc)) {
                dsl_deadlist_open(&ll, mos, attr.za_first_integer);
                func(&ll, arg);
                dsl_deadlist_close(&ll);
        }
        zap_cursor_fini(&zc);
}

static int
bpobj_count_block_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
    dmu_tx_t *tx)
{
        ASSERT(!bp_freed);
        return (count_block_cb(arg, bp, tx));
}

static int
livelist_entry_count_blocks_cb(void *args, dsl_deadlist_entry_t *dle)
{
        zdb_cb_t *zbc = args;
        bplist_t blks;
        bplist_create(&blks);
        /* determine which blocks have been alloc'd but not freed */
        VERIFY0(dsl_process_sub_livelist(&dle->dle_bpobj, &blks, NULL, NULL));
        /* count those blocks */
        (void) bplist_iterate(&blks, count_block_cb, zbc, NULL);
        bplist_destroy(&blks);
        return (0);
}

static void
livelist_count_blocks(dsl_deadlist_t *ll, void *arg)
{
        dsl_deadlist_iterate(ll, livelist_entry_count_blocks_cb, arg);
}

/*
 * Count the blocks in the livelists that have been destroyed by the user
 * but haven't yet been freed.
 */
static void
deleted_livelists_count_blocks(spa_t *spa, zdb_cb_t *zbc)
{
        iterate_deleted_livelists(spa, livelist_count_blocks, zbc);
}

static void
dump_livelist_cb(dsl_deadlist_t *ll, void *arg)
{
        ASSERT3P(arg, ==, NULL);
        global_feature_count[SPA_FEATURE_LIVELIST]++;
        dump_blkptr_list(ll, "Deleted Livelist");
        dsl_deadlist_iterate(ll, sublivelist_verify_lightweight, NULL);
}

/*
 * Print out, register object references to, and increment feature counts for
 * livelists that have been destroyed by the user but haven't yet been freed.
 */
static void
deleted_livelists_dump_mos(spa_t *spa)
{
        uint64_t zap_obj;
        objset_t *mos = spa->spa_meta_objset;
        int err = zap_lookup(mos, DMU_POOL_DIRECTORY_OBJECT,
            DMU_POOL_DELETED_CLONES, sizeof (uint64_t), 1, &zap_obj);
        if (err == ENOENT)
                return;
        mos_obj_refd(zap_obj);
        iterate_deleted_livelists(spa, dump_livelist_cb, NULL);
}

static int
dump_block_stats(spa_t *spa)
{
        zdb_cb_t zcb = {{{{0}}}};
        zdb_blkstats_t *zb, *tzb;
        uint64_t norm_alloc, norm_space, total_alloc, total_found;
        int flags = TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA |
            TRAVERSE_NO_DECRYPT | TRAVERSE_HARD;
        boolean_t leaks = B_FALSE;
        int e, c, err;
        bp_embedded_type_t i;

        (void) printf("\nTraversing all blocks %s%s%s%s%s...\n\n",
            (dump_opt['c'] || !dump_opt['L']) ? "to verify " : "",
            (dump_opt['c'] == 1) ? "metadata " : "",
            dump_opt['c'] ? "checksums " : "",
            (dump_opt['c'] && !dump_opt['L']) ? "and verify " : "",
            !dump_opt['L'] ? "nothing leaked " : "");

        /*
         * When leak detection is enabled we load all space maps as SM_ALLOC
         * maps, then traverse the pool claiming each block we discover. If
         * the pool is perfectly consistent, the segment trees will be empty
         * when we're done. Anything left over is a leak; any block we can't
         * claim (because it's not part of any space map) is a double
         * allocation, reference to a freed block, or an unclaimed log block.
         *
         * When leak detection is disabled (-L option) we still traverse the
         * pool claiming each block we discover, but we skip opening any space
         * maps.
         */
        zdb_leak_init(spa, &zcb);

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

        if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
                (void) bpobj_iterate_nofree(&spa->spa_dsl_pool->dp_free_bpobj,
                    bpobj_count_block_cb, &zcb, NULL);
        }

        zdb_claim_removing(spa, &zcb);

        if (spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) {
                VERIFY3U(0, ==, bptree_iterate(spa->spa_meta_objset,
                    spa->spa_dsl_pool->dp_bptree_obj, B_FALSE, count_block_cb,
                    &zcb, NULL));
        }

        deleted_livelists_count_blocks(spa, &zcb);

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

        zcb.zcb_totalasize = metaslab_class_get_alloc(spa_normal_class(spa));
        zcb.zcb_totalasize += metaslab_class_get_alloc(spa_special_class(spa));
        zcb.zcb_totalasize += metaslab_class_get_alloc(spa_dedup_class(spa));
        zcb.zcb_totalasize +=
            metaslab_class_get_alloc(spa_embedded_log_class(spa));
        zcb.zcb_start = zcb.zcb_lastprint = gethrtime();
        err = traverse_pool(spa, 0, flags, zdb_blkptr_cb, &zcb);

        /*
         * If we've traversed the data blocks then we need to wait for those
         * I/Os to complete. We leverage "The Godfather" zio to wait on
         * all async I/Os to complete.
         */
        if (dump_opt['c']) {
                for (c = 0; c < max_ncpus; c++) {
                        (void) zio_wait(spa->spa_async_zio_root[c]);
                        spa->spa_async_zio_root[c] = zio_root(spa, NULL, NULL,
                            ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
                            ZIO_FLAG_GODFATHER);
                }
        }
        ASSERT0(spa->spa_load_verify_bytes);

        /*
         * Done after zio_wait() since zcb_haderrors is modified in
         * zdb_blkptr_done()
         */
        zcb.zcb_haderrors |= err;

        if (zcb.zcb_haderrors) {
                (void) printf("\nError counts:\n\n");
                (void) printf("\t%5s  %s\n", "errno", "count");
                for (e = 0; e < 256; e++) {
                        if (zcb.zcb_errors[e] != 0) {
                                (void) printf("\t%5d  %llu\n",
                                    e, (u_longlong_t)zcb.zcb_errors[e]);
                        }
                }
        }

        /*
         * Report any leaked segments.
         */
        leaks |= zdb_leak_fini(spa, &zcb);

        tzb = &zcb.zcb_type[ZB_TOTAL][ZDB_OT_TOTAL];

        norm_alloc = metaslab_class_get_alloc(spa_normal_class(spa));
        norm_space = metaslab_class_get_space(spa_normal_class(spa));

        total_alloc = norm_alloc +
            metaslab_class_get_alloc(spa_log_class(spa)) +
            metaslab_class_get_alloc(spa_embedded_log_class(spa)) +
            metaslab_class_get_alloc(spa_special_class(spa)) +
            metaslab_class_get_alloc(spa_dedup_class(spa)) +
            get_unflushed_alloc_space(spa);
        total_found = tzb->zb_asize - zcb.zcb_dedup_asize +
            zcb.zcb_removing_size + zcb.zcb_checkpoint_size;

        if (total_found == total_alloc && !dump_opt['L']) {
                (void) printf("\n\tNo leaks (block sum matches space"
                    " maps exactly)\n");
        } else if (!dump_opt['L']) {
                (void) printf("block traversal size %llu != alloc %llu "
                    "(%s %lld)\n",
                    (u_longlong_t)total_found,
                    (u_longlong_t)total_alloc,
                    (dump_opt['L']) ? "unreachable" : "leaked",
                    (longlong_t)(total_alloc - total_found));
                leaks = B_TRUE;
        }

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

        (void) printf("\n");
        (void) printf("\t%-16s %14llu\n", "bp count:",
            (u_longlong_t)tzb->zb_count);
        (void) printf("\t%-16s %14llu\n", "ganged count:",
            (longlong_t)tzb->zb_gangs);
        (void) printf("\t%-16s %14llu      avg: %6llu\n", "bp logical:",
            (u_longlong_t)tzb->zb_lsize,
            (u_longlong_t)(tzb->zb_lsize / tzb->zb_count));
        (void) printf("\t%-16s %14llu      avg: %6llu     compression: %6.2f\n",
            "bp physical:", (u_longlong_t)tzb->zb_psize,
            (u_longlong_t)(tzb->zb_psize / tzb->zb_count),
            (double)tzb->zb_lsize / tzb->zb_psize);
        (void) printf("\t%-16s %14llu      avg: %6llu     compression: %6.2f\n",
            "bp allocated:", (u_longlong_t)tzb->zb_asize,
            (u_longlong_t)(tzb->zb_asize / tzb->zb_count),
            (double)tzb->zb_lsize / tzb->zb_asize);
        (void) printf("\t%-16s %14llu    ref>1: %6llu   deduplication: %6.2f\n",
            "bp deduped:", (u_longlong_t)zcb.zcb_dedup_asize,
            (u_longlong_t)zcb.zcb_dedup_blocks,
            (double)zcb.zcb_dedup_asize / tzb->zb_asize + 1.0);
        (void) printf("\t%-16s %14llu     used: %5.2f%%\n", "Normal class:",
            (u_longlong_t)norm_alloc, 100.0 * norm_alloc / norm_space);

        if (spa_special_class(spa)->mc_allocator[0].mca_rotor != NULL) {
                uint64_t alloc = metaslab_class_get_alloc(
                    spa_special_class(spa));
                uint64_t space = metaslab_class_get_space(
                    spa_special_class(spa));

                (void) printf("\t%-16s %14llu     used: %5.2f%%\n",
                    "Special class", (u_longlong_t)alloc,
                    100.0 * alloc / space);
        }

        if (spa_dedup_class(spa)->mc_allocator[0].mca_rotor != NULL) {
                uint64_t alloc = metaslab_class_get_alloc(
                    spa_dedup_class(spa));
                uint64_t space = metaslab_class_get_space(
                    spa_dedup_class(spa));

                (void) printf("\t%-16s %14llu     used: %5.2f%%\n",
                    "Dedup class", (u_longlong_t)alloc,
                    100.0 * alloc / space);
        }

        if (spa_embedded_log_class(spa)->mc_allocator[0].mca_rotor != NULL) {
                uint64_t alloc = metaslab_class_get_alloc(
                    spa_embedded_log_class(spa));
                uint64_t space = metaslab_class_get_space(
                    spa_embedded_log_class(spa));

                (void) printf("\t%-16s %14llu     used: %5.2f%%\n",
                    "Embedded log class", (u_longlong_t)alloc,
                    100.0 * alloc / space);
        }

        for (i = 0; i < NUM_BP_EMBEDDED_TYPES; i++) {
                if (zcb.zcb_embedded_blocks[i] == 0)
                        continue;
                (void) printf("\n");
                (void) printf("\tadditional, non-pointer bps of type %u: "
                    "%10llu\n",
                    i, (u_longlong_t)zcb.zcb_embedded_blocks[i]);

                if (dump_opt['b'] >= 3) {
                        (void) printf("\t number of (compressed) bytes:  "
                            "number of bps\n");
                        dump_histogram(zcb.zcb_embedded_histogram[i],
                            sizeof (zcb.zcb_embedded_histogram[i]) /
                            sizeof (zcb.zcb_embedded_histogram[i][0]), 0);
                }
        }

        if (tzb->zb_ditto_samevdev != 0) {
                (void) printf("\tDittoed blocks on same vdev: %llu\n",
                    (longlong_t)tzb->zb_ditto_samevdev);
        }
        if (tzb->zb_ditto_same_ms != 0) {
                (void) printf("\tDittoed blocks in same metaslab: %llu\n",
                    (longlong_t)tzb->zb_ditto_same_ms);
        }

        for (uint64_t v = 0; v < spa->spa_root_vdev->vdev_children; v++) {
                vdev_t *vd = spa->spa_root_vdev->vdev_child[v];
                vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;

                if (vim == NULL) {
                        continue;
                }

                char mem[32];
                zdb_nicenum(vdev_indirect_mapping_num_entries(vim),
                    mem, vdev_indirect_mapping_size(vim));

                (void) printf("\tindirect vdev id %llu has %llu segments "
                    "(%s in memory)\n",
                    (longlong_t)vd->vdev_id,
                    (longlong_t)vdev_indirect_mapping_num_entries(vim), mem);
        }

        if (dump_opt['b'] >= 2) {
                int l, t, level;
                (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 */
                        _Static_assert(sizeof (csize) >= NN_NUMBUF_SZ,
                            "csize truncated");
                        _Static_assert(sizeof (lsize) >= NN_NUMBUF_SZ,
                            "lsize truncated");
                        _Static_assert(sizeof (psize) >= NN_NUMBUF_SZ,
                            "psize truncated");
                        _Static_assert(sizeof (asize) >= NN_NUMBUF_SZ,
                            "asize truncated");
                        _Static_assert(sizeof (avg) >= NN_NUMBUF_SZ,
                            "avg truncated");
                        _Static_assert(sizeof (gang) >= NN_NUMBUF_SZ,
                            "gang truncated");

                        if (t < DMU_OT_NUMTYPES)
                                typename = dmu_ot[t].ot_name;
                        else
                                typename = zdb_ot_extname[t - DMU_OT_NUMTYPES];

                        if (zcb.zcb_type[ZB_TOTAL][t].zb_asize == 0) {
                                (void) printf("%6s\t%5s\t%5s\t%5s"
                                    "\t%5s\t%5s\t%6s\t%s\n",
                                    "-",
                                    "-",
                                    "-",
                                    "-",
                                    "-",
                                    "-",
                                    "-",
                                    typename);
                                continue;
                        }

                        for (l = ZB_TOTAL - 1; l >= -1; l--) {
                                level = (l == -1 ? ZB_TOTAL : l);
                                zb = &zcb.zcb_type[level][t];

                                if (zb->zb_asize == 0)
                                        continue;

                                if (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);
                                }
                        }
                }

                /* Output a table summarizing block sizes in the pool */
                if (dump_opt['b'] >= 2) {
                        dump_size_histograms(&zcb);
                }
        }

        (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;

static int
zdb_ddt_add_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
    const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
{
        (void) zilog, (void) dnp;
        avl_tree_t *t = arg;
        avl_index_t where;
        zdb_ddt_entry_t *zdde, zdde_search;

        if (zb->zb_level == ZB_DNODE_LEVEL || BP_IS_HOLE(bp) ||
            BP_IS_EMBEDDED(bp))
                return (0);

        if (dump_opt['S'] > 1 && zb->zb_level == ZB_ROOT_LEVEL) {
                (void) printf("traversing objset %llu, %llu objects, "
                    "%lu blocks so far\n",
                    (u_longlong_t)zb->zb_objset,
                    (u_longlong_t)BP_GET_FILL(bp),
                    avl_numnodes(t));
        }

        if (BP_IS_HOLE(bp) || BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_OFF ||
            BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))
                return (0);

        ddt_key_fill(&zdde_search.zdde_key, bp);

        zdde = avl_find(t, &zdde_search, &where);

        if (zdde == NULL) {
                zdde = umem_zalloc(sizeof (*zdde), UMEM_NOFAIL);
                zdde->zdde_key = zdde_search.zdde_key;
                avl_insert(t, zdde, where);
        }

        zdde->zdde_ref_blocks += 1;
        zdde->zdde_ref_lsize += BP_GET_LSIZE(bp);
        zdde->zdde_ref_psize += BP_GET_PSIZE(bp);
        zdde->zdde_ref_dsize += bp_get_dsize_sync(spa, bp);

        return (0);
}

static void
dump_simulated_ddt(spa_t *spa)
{
        avl_tree_t t;
        void *cookie = NULL;
        zdb_ddt_entry_t *zdde;
        ddt_histogram_t ddh_total = {{{0}}};
        ddt_stat_t dds_total = {0};

        avl_create(&t, ddt_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 |
            TRAVERSE_NO_DECRYPT, 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));
                        dump_spacemap(spa->spa_meta_objset, prev_obsolete_sm);
                        (void) printf("\n");
                        space_map_close(prev_obsolete_sm);
                }

                scip_count += 2;
        }

        for (uint64_t i = 0; i < spa->spa_root_vdev->vdev_children; i++) {
                vdev_t *vd = spa->spa_root_vdev->vdev_child[i];
                vdev_indirect_config_t *vic = &vd->vdev_indirect_config;

                if (vic->vic_mapping_object != 0) {
                        ASSERT(vd->vdev_ops == &vdev_indirect_ops ||
                            vd->vdev_removing);
                        indirect_vdev_count++;

                        if (vd->vdev_indirect_mapping->vim_havecounts) {
                                obsolete_counts_count++;
                        }
                }

                boolean_t are_precise;
                VERIFY0(vdev_obsolete_counts_are_precise(vd, &are_precise));
                if (are_precise) {
                        ASSERT(vic->vic_mapping_object != 0);
                        precise_vdev_count++;
                }

                uint64_t obsolete_sm_object;
                VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
                if (obsolete_sm_object != 0) {
                        ASSERT(vic->vic_mapping_object != 0);
                        obsolete_sm_count++;
                }
        }

        (void) feature_get_refcount(spa,
            &spa_feature_table[SPA_FEATURE_DEVICE_REMOVAL],
            &dr_feature_refcount);
        (void) feature_get_refcount(spa,
            &spa_feature_table[SPA_FEATURE_OBSOLETE_COUNTS],
            &oc_feature_refcount);

        if (dr_feature_refcount != indirect_vdev_count) {
                ret = 1;
                (void) printf("Number of indirect vdevs (%llu) " \
                    "does not match feature count (%llu)\n",
                    (u_longlong_t)indirect_vdev_count,
                    (u_longlong_t)dr_feature_refcount);
        } else {
                (void) printf("Verified device_removal feature refcount " \
                    "of %llu is correct\n",
                    (u_longlong_t)dr_feature_refcount);
        }

        if (zap_contains(spa_meta_objset(spa), DMU_POOL_DIRECTORY_OBJECT,
            DMU_POOL_OBSOLETE_BPOBJ) == 0) {
                obsolete_bpobj_count++;
        }


        obsolete_counts_object_count = precise_vdev_count;
        obsolete_counts_object_count += obsolete_sm_count;
        obsolete_counts_object_count += obsolete_counts_count;
        obsolete_counts_object_count += scip_count;
        obsolete_counts_object_count += obsolete_bpobj_count;
        obsolete_counts_object_count += remap_deadlist_count;

        if (oc_feature_refcount != obsolete_counts_object_count) {
                ret = 1;
                (void) printf("Number of obsolete counts objects (%llu) " \
                    "does not match feature count (%llu)\n",
                    (u_longlong_t)obsolete_counts_object_count,
                    (u_longlong_t)oc_feature_refcount);
                (void) printf("pv:%llu os:%llu oc:%llu sc:%llu "
                    "ob:%llu rd:%llu\n",
                    (u_longlong_t)precise_vdev_count,
                    (u_longlong_t)obsolete_sm_count,
                    (u_longlong_t)obsolete_counts_count,
                    (u_longlong_t)scip_count,
                    (u_longlong_t)obsolete_bpobj_count,
                    (u_longlong_t)remap_deadlist_count);
        } else {
                (void) printf("Verified indirect_refcount feature refcount " \
                    "of %llu is correct\n",
                    (u_longlong_t)oc_feature_refcount);
        }
        return (ret);
}

static void
zdb_set_skip_mmp(char *target)
{
        spa_t *spa;

        /*
         * Disable the activity check to allow examination of
         * active pools.
         */
        mutex_enter(&spa_namespace_lock);
        if ((spa = spa_lookup(target)) != NULL) {
                spa->spa_import_flags |= ZFS_IMPORT_SKIP_MMP;
        }
        mutex_exit(&spa_namespace_lock);
}

#define BOGUS_SUFFIX "_CHECKPOINTED_UNIVERSE"
/*
 * Import the checkpointed state of the pool specified by the target
 * parameter as readonly. The function also accepts a pool config
 * as an optional parameter, else it attempts to infer the config by
 * the name of the target pool.
 *
 * Note that the checkpointed state's pool name will be the name of
 * the original pool with the above suffix appended to it. In addition,
 * if the target is not a pool name (e.g. a path to a dataset) then
 * the new_path parameter is populated with the updated path to
 * reflect the fact that we are looking into the checkpointed state.
 *
 * The function returns a newly-allocated copy of the name of the
 * pool containing the checkpointed state. When this copy is no
 * longer needed it should be freed with free(3C). Same thing
 * applies to the new_path parameter if allocated.
 */
static char *
import_checkpointed_state(char *target, nvlist_t *cfg, char **new_path)
{
        int error = 0;
        char *poolname, *bogus_name = NULL;
        boolean_t freecfg = B_FALSE;

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

        if (cfg == NULL) {
                zdb_set_skip_mmp(poolname);
                error = spa_get_stats(poolname, &cfg, NULL, 0);
                if (error != 0) {
                        fatal("Tried to read config of pool \"%s\" but "
                            "spa_get_stats() failed with error %d\n",
                            poolname, error);
                }
                freecfg = B_TRUE;
        }

        if (asprintf(&bogus_name, "%s%s", poolname, BOGUS_SUFFIX) == -1)
                return (NULL);
        fnvlist_add_string(cfg, ZPOOL_CONFIG_POOL_NAME, bogus_name);

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

        if (new_path != NULL && path_start != NULL) {
                if (asprintf(new_path, "%s%s", bogus_name, path_start) == -1) {
                        if (path_start != NULL)
                                free(poolname);
                        return (NULL);
                }
        }

        if (target != poolname)
                free(poolname);

        return (bogus_name);
}

typedef struct verify_checkpoint_sm_entry_cb_arg {
        vdev_t *vcsec_vd;

        /* the following fields are only used for printing progress */
        uint64_t vcsec_entryid;
        uint64_t vcsec_num_entries;
} verify_checkpoint_sm_entry_cb_arg_t;

#define ENTRIES_PER_PROGRESS_UPDATE 10000

static int
verify_checkpoint_sm_entry_cb(space_map_entry_t *sme, void *arg)
{
        verify_checkpoint_sm_entry_cb_arg_t *vcsec = arg;
        vdev_t *vd = vcsec->vcsec_vd;
        metaslab_t *ms = vd->vdev_ms[sme->sme_offset >> vd->vdev_ms_shift];
        uint64_t end = sme->sme_offset + sme->sme_run;

        ASSERT(sme->sme_type == SM_FREE);

        if ((vcsec->vcsec_entryid % ENTRIES_PER_PROGRESS_UPDATE) == 0) {
                (void) fprintf(stderr,
                    "\rverifying vdev %llu, space map entry %llu of %llu ...",
                    (longlong_t)vd->vdev_id,
                    (longlong_t)vcsec->vcsec_entryid,
                    (longlong_t)vcsec->vcsec_num_entries);
        }
        vcsec->vcsec_entryid++;

        /*
         * See comment in checkpoint_sm_exclude_entry_cb()
         */
        VERIFY3U(sme->sme_offset, >=, ms->ms_start);
        VERIFY3U(end, <=, ms->ms_start + ms->ms_size);

        /*
         * The entries in the vdev_checkpoint_sm should be marked as
         * allocated in the checkpointed state of the pool, therefore
         * their respective ms_allocateable trees should not contain them.
         */
        mutex_enter(&ms->ms_lock);
        range_tree_verify_not_present(ms->ms_allocatable,
            sme->sme_offset, sme->sme_run);
        mutex_exit(&ms->ms_lock);

        return (0);
}

/*
 * Verify that all segments in the vdev_checkpoint_sm are allocated
 * according to the checkpoint's ms_sm (i.e. are not in the checkpoint's
 * ms_allocatable).
 *
 * Do so by comparing the checkpoint space maps (vdev_checkpoint_sm) of
 * each vdev in the current state of the pool to the metaslab space maps
 * (ms_sm) of the checkpointed state of the pool.
 *
 * Note that the function changes the state of the ms_allocatable
 * trees of the current spa_t. The entries of these ms_allocatable
 * trees are cleared out and then repopulated from with the free
 * entries of their respective ms_sm space maps.
 */
static void
verify_checkpoint_vdev_spacemaps(spa_t *checkpoint, spa_t *current)
{
        vdev_t *ckpoint_rvd = checkpoint->spa_root_vdev;
        vdev_t *current_rvd = current->spa_root_vdev;

        load_concrete_ms_allocatable_trees(checkpoint, SM_FREE);

        for (uint64_t c = 0; c < ckpoint_rvd->vdev_children; c++) {
                vdev_t *ckpoint_vd = ckpoint_rvd->vdev_child[c];
                vdev_t *current_vd = current_rvd->vdev_child[c];

                space_map_t *checkpoint_sm = NULL;
                uint64_t checkpoint_sm_obj;

                if (ckpoint_vd->vdev_ops == &vdev_indirect_ops) {
                        /*
                         * Since we don't allow device removal in a pool
                         * that has a checkpoint, we expect that all removed
                         * vdevs were removed from the pool before the
                         * checkpoint.
                         */
                        ASSERT3P(current_vd->vdev_ops, ==, &vdev_indirect_ops);
                        continue;
                }

                /*
                 * If the checkpoint space map doesn't exist, then nothing
                 * here is checkpointed so there's nothing to verify.
                 */
                if (current_vd->vdev_top_zap == 0 ||
                    zap_contains(spa_meta_objset(current),
                    current_vd->vdev_top_zap,
                    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM) != 0)
                        continue;

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

                VERIFY0(space_map_open(&checkpoint_sm, spa_meta_objset(current),
                    checkpoint_sm_obj, 0, current_vd->vdev_asize,
                    current_vd->vdev_ashift));

                verify_checkpoint_sm_entry_cb_arg_t vcsec;
                vcsec.vcsec_vd = ckpoint_vd;
                vcsec.vcsec_entryid = 0;
                vcsec.vcsec_num_entries =
                    space_map_length(checkpoint_sm) / sizeof (uint64_t);
                VERIFY0(space_map_iterate(checkpoint_sm,
                    space_map_length(checkpoint_sm),
                    verify_checkpoint_sm_entry_cb, &vcsec));
                if (dump_opt['m'] > 3)
                        dump_spacemap(current->spa_meta_objset, checkpoint_sm);
                space_map_close(checkpoint_sm);
        }

        /*
         * If we've added vdevs since we took the checkpoint, ensure
         * that their checkpoint space maps are empty.
         */
        if (ckpoint_rvd->vdev_children < current_rvd->vdev_children) {
                for (uint64_t c = ckpoint_rvd->vdev_children;
                    c < current_rvd->vdev_children; c++) {
                        vdev_t *current_vd = current_rvd->vdev_child[c];
                        VERIFY3P(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_not_present,
                            current_msp->ms_allocatable);
                }
        }

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

static void
verify_checkpoint_blocks(spa_t *spa)
{
        ASSERT(!dump_opt['L']);

        spa_t *checkpoint_spa;
        char *checkpoint_pool;
        int error = 0;

        /*
         * We import the checkpointed state of the pool (under a different
         * name) so we can do verification on it against the current state
         * of the pool.
         */
        checkpoint_pool = import_checkpointed_state(spa->spa_name, NULL,
            NULL);
        ASSERT(strcmp(spa->spa_name, checkpoint_pool) != 0);

        error = spa_open(checkpoint_pool, &checkpoint_spa, FTAG);
        if (error != 0) {
                fatal("Tried to open pool \"%s\" but spa_open() failed with "
                    "error %d\n", checkpoint_pool, error);
        }

        /*
         * Ensure that ranges in the checkpoint space maps of each vdev
         * are allocated according to the checkpointed state's metaslab
         * space maps.
         */
        verify_checkpoint_vdev_spacemaps(checkpoint_spa, spa);

        /*
         * Ensure that allocated ranges in the checkpoint's metaslab
         * space maps remain allocated in the metaslab space maps of
         * the current state.
         */
        verify_checkpoint_ms_spacemaps(checkpoint_spa, spa);

        /*
         * Once we are done, we get rid of the checkpointed state.
         */
        spa_close(checkpoint_spa, FTAG);
        free(checkpoint_pool);
}

static void
dump_leftover_checkpoint_blocks(spa_t *spa)
{
        vdev_t *rvd = spa->spa_root_vdev;

        for (uint64_t i = 0; i < rvd->vdev_children; i++) {
                vdev_t *vd = rvd->vdev_child[i];

                space_map_t *checkpoint_sm = NULL;
                uint64_t checkpoint_sm_obj;

                if (vd->vdev_top_zap == 0)
                        continue;

                if (zap_contains(spa_meta_objset(spa), vd->vdev_top_zap,
                    VDEV_TOP_ZAP_POOL_CHECKPOINT_SM) != 0)
                        continue;

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

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

static int
verify_checkpoint(spa_t *spa)
{
        uberblock_t checkpoint;
        int error;

        if (!spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT))
                return (0);

        error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
            DMU_POOL_ZPOOL_CHECKPOINT, sizeof (uint64_t),
            sizeof (uberblock_t) / sizeof (uint64_t), &checkpoint);

        if (error == ENOENT && !dump_opt['L']) {
                /*
                 * If the feature is active but the uberblock is missing
                 * then we must be in the middle of discarding the
                 * checkpoint.
                 */
                (void) printf("\nPartially discarded checkpoint "
                    "state found:\n");
                if (dump_opt['m'] > 3)
                        dump_leftover_checkpoint_blocks(spa);
                return (0);
        } else if (error != 0) {
                (void) printf("lookup error %d when looking for "
                    "checkpointed uberblock in MOS\n", error);
                return (error);
        }
        dump_uberblock(&checkpoint, "\nCheckpointed uberblock found:\n", "\n");

        if (checkpoint.ub_checkpoint_txg == 0) {
                (void) printf("\nub_checkpoint_txg not set in checkpointed "
                    "uberblock\n");
                error = 3;
        }

        if (error == 0 && !dump_opt['L'])
                verify_checkpoint_blocks(spa);

        return (error);
}

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

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

/*
 * Call on a MOS object that may already have been referenced.
 */
static void
mos_obj_refd_multiple(uint64_t obj)
{
        if (obj != 0 && mos_refd_objs != NULL &&
            !range_tree_contains(mos_refd_objs, obj, 1))
                range_tree_add(mos_refd_objs, obj, 1);
}

static void
mos_leak_vdev_top_zap(vdev_t *vd)
{
        uint64_t ms_flush_data_obj;
        int error = zap_lookup(spa_meta_objset(vd->vdev_spa),
            vd->vdev_top_zap, VDEV_TOP_ZAP_MS_UNFLUSHED_PHYS_TXGS,
            sizeof (ms_flush_data_obj), 1, &ms_flush_data_obj);
        if (error == ENOENT)
                return;
        ASSERT0(error);

        mos_obj_refd(ms_flush_data_obj);
}

static void
mos_leak_vdev(vdev_t *vd)
{
        mos_obj_refd(vd->vdev_dtl_object);
        mos_obj_refd(vd->vdev_ms_array);
        mos_obj_refd(vd->vdev_indirect_config.vic_births_object);
        mos_obj_refd(vd->vdev_indirect_config.vic_mapping_object);
        mos_obj_refd(vd->vdev_leaf_zap);
        if (vd->vdev_checkpoint_sm != NULL)
                mos_obj_refd(vd->vdev_checkpoint_sm->sm_object);
        if (vd->vdev_indirect_mapping != NULL) {
                mos_obj_refd(vd->vdev_indirect_mapping->
                    vim_phys->vimp_counts_object);
        }
        if (vd->vdev_obsolete_sm != NULL)
                mos_obj_refd(vd->vdev_obsolete_sm->sm_object);

        for (uint64_t m = 0; m < vd->vdev_ms_count; m++) {
                metaslab_t *ms = vd->vdev_ms[m];
                mos_obj_refd(space_map_object(ms->ms_sm));
        }

        if (vd->vdev_top_zap != 0) {
                mos_obj_refd(vd->vdev_top_zap);
                mos_leak_vdev_top_zap(vd);
        }

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

static void
mos_leak_log_spacemaps(spa_t *spa)
{
        uint64_t spacemap_zap;
        int error = zap_lookup(spa_meta_objset(spa),
            DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_LOG_SPACEMAP_ZAP,
            sizeof (spacemap_zap), 1, &spacemap_zap);
        if (error == ENOENT)
                return;
        ASSERT0(error);

        mos_obj_refd(spacemap_zap);
        for (spa_log_sm_t *sls = avl_first(&spa->spa_sm_logs_by_txg);
            sls; sls = AVL_NEXT(&spa->spa_sm_logs_by_txg, sls))
                mos_obj_refd(sls->sls_sm_obj);
}

static 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);

        if (spa->spa_syncing_log_sm != NULL)
                mos_obj_refd(spa->spa_syncing_log_sm->sm_object);
        mos_leak_log_spacemaps(spa);

        mos_obj_refd(spa->spa_condensing_indirect_phys.
            scip_next_mapping_object);
        mos_obj_refd(spa->spa_condensing_indirect_phys.
            scip_prev_obsolete_sm_object);
        if (spa->spa_condensing_indirect_phys.scip_next_mapping_object != 0) {
                vdev_indirect_mapping_t *vim =
                    vdev_indirect_mapping_open(mos,
                    spa->spa_condensing_indirect_phys.scip_next_mapping_object);
                mos_obj_refd(vim->vim_phys->vimp_counts_object);
                vdev_indirect_mapping_close(vim);
        }
        deleted_livelists_dump_mos(spa);

        if (dp->dp_origin_snap != NULL) {
                dsl_dataset_t *ds;

                dsl_pool_config_enter(dp, FTAG);
                VERIFY0(dsl_dataset_hold_obj(dp,
                    dsl_dataset_phys(dp->dp_origin_snap)->ds_next_snap_obj,
                    FTAG, &ds));
                count_ds_mos_objects(ds);
                dump_blkptr_list(&ds->ds_deadlist, "Deadlist");
                dsl_dataset_rele(ds, FTAG);
                dsl_pool_config_exit(dp, FTAG);

                count_ds_mos_objects(dp->dp_origin_snap);
                dump_blkptr_list(&dp->dp_origin_snap->ds_deadlist, "Deadlist");
        }
        count_dir_mos_objects(dp->dp_mos_dir);
        if (dp->dp_free_dir != NULL)
                count_dir_mos_objects(dp->dp_free_dir);
        if (dp->dp_leak_dir != NULL)
                count_dir_mos_objects(dp->dp_leak_dir);

        mos_leak_vdev(spa->spa_root_vdev);

        for (uint64_t 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);
}

typedef struct log_sm_obsolete_stats_arg {
        uint64_t lsos_current_txg;

        uint64_t lsos_total_entries;
        uint64_t lsos_valid_entries;

        uint64_t lsos_sm_entries;
        uint64_t lsos_valid_sm_entries;
} log_sm_obsolete_stats_arg_t;

static int
log_spacemap_obsolete_stats_cb(spa_t *spa, space_map_entry_t *sme,
    uint64_t txg, void *arg)
{
        log_sm_obsolete_stats_arg_t *lsos = arg;

        uint64_t offset = sme->sme_offset;
        uint64_t vdev_id = sme->sme_vdev;

        if (lsos->lsos_current_txg == 0) {
                /* this is the first log */
                lsos->lsos_current_txg = txg;
        } else if (lsos->lsos_current_txg < txg) {
                /* we just changed log - print stats and reset */
                (void) printf("%-8llu valid entries out of %-8llu - txg %llu\n",
                    (u_longlong_t)lsos->lsos_valid_sm_entries,
                    (u_longlong_t)lsos->lsos_sm_entries,
                    (u_longlong_t)lsos->lsos_current_txg);
                lsos->lsos_valid_sm_entries = 0;
                lsos->lsos_sm_entries = 0;
                lsos->lsos_current_txg = txg;
        }
        ASSERT3U(lsos->lsos_current_txg, ==, txg);

        lsos->lsos_sm_entries++;
        lsos->lsos_total_entries++;

        vdev_t *vd = vdev_lookup_top(spa, vdev_id);
        if (!vdev_is_concrete(vd))
                return (0);

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

        if (txg < metaslab_unflushed_txg(ms))
                return (0);
        lsos->lsos_valid_sm_entries++;
        lsos->lsos_valid_entries++;
        return (0);
}

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

        log_sm_obsolete_stats_arg_t lsos = {0};

        (void) printf("Log Space Map Obsolete Entry Statistics:\n");

        iterate_through_spacemap_logs(spa,
            log_spacemap_obsolete_stats_cb, &lsos);

        /* print stats for latest log */
        (void) printf("%-8llu valid entries out of %-8llu - txg %llu\n",
            (u_longlong_t)lsos.lsos_valid_sm_entries,
            (u_longlong_t)lsos.lsos_sm_entries,
            (u_longlong_t)lsos.lsos_current_txg);

        (void) printf("%-8llu valid entries out of %-8llu - total\n\n",
            (u_longlong_t)lsos.lsos_valid_entries,
            (u_longlong_t)lsos.lsos_total_entries);
}

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

        if (dump_opt['y']) {
                livelist_metaslab_validate(spa);
        }

        if (dump_opt['S']) {
                dump_simulated_ddt(spa);
                return;
        }

        if (!dump_opt['e'] && dump_opt['C'] > 1) {
                (void) printf("\nCached configuration:\n");
                dump_nvlist(spa->spa_config, 8);
        }

        if (dump_opt['C'])
                dump_config(spa);

        if (dump_opt['u'])
                dump_uberblock(&spa->spa_uberblock, "\nUberblock:\n", "\n");

        if (dump_opt['D'])
                dump_all_ddts(spa);

        if (dump_opt['d'] > 2 || dump_opt['m'])
                dump_metaslabs(spa);
        if (dump_opt['M'])
                dump_metaslab_groups(spa, dump_opt['M'] > 1);
        if (dump_opt['d'] > 2 || dump_opt['m']) {
                dump_log_spacemaps(spa);
                dump_log_spacemap_obsolete_stats(spa);
        }

        if (dump_opt['d'] || dump_opt['i']) {
                spa_feature_t f;
                mos_refd_objs = range_tree_create(NULL, RANGE_SEG64, NULL, 0,
                    0);
                dump_objset(dp->dp_meta_objset);

                if (dump_opt['d'] >= 3) {
                        dsl_pool_t *dp = spa->spa_dsl_pool;
                        dump_full_bpobj(&spa->spa_deferred_bpobj,
                            "Deferred frees", 0);
                        if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
                                dump_full_bpobj(&dp->dp_free_bpobj,
                                    "Pool snapshot frees", 0);
                        }
                        if (bpobj_is_open(&dp->dp_obsolete_bpobj)) {
                                ASSERT(spa_feature_is_enabled(spa,
                                    SPA_FEATURE_DEVICE_REMOVAL));
                                dump_full_bpobj(&dp->dp_obsolete_bpobj,
                                    "Pool obsolete blocks", 0);
                        }

                        if (spa_feature_is_active(spa,
                            SPA_FEATURE_ASYNC_DESTROY)) {
                                dump_bptree(spa->spa_meta_objset,
                                    dp->dp_bptree_obj,
                                    "Pool dataset frees");
                        }
                        dump_dtl(spa->spa_root_vdev, 0);
                }

                for (spa_feature_t f = 0; f < SPA_FEATURES; f++)
                        global_feature_count[f] = UINT64_MAX;
                global_feature_count[SPA_FEATURE_REDACTION_BOOKMARKS] = 0;
                global_feature_count[SPA_FEATURE_BOOKMARK_WRITTEN] = 0;
                global_feature_count[SPA_FEATURE_LIVELIST] = 0;

                (void) dmu_objset_find(spa_name(spa), dump_one_objset,
                    NULL, DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);

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

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

                        uint64_t *arr;
                        if (!(spa_feature_table[f].fi_flags &
                            ZFEATURE_FLAG_PER_DATASET)) {
                                if (global_feature_count[f] == UINT64_MAX)
                                        continue;
                                if (!spa_feature_is_enabled(spa, f)) {
                                        ASSERT0(global_feature_count[f]);
                                        continue;
                                }
                                arr = global_feature_count;
                        } else {
                                if (!spa_feature_is_enabled(spa, f)) {
                                        ASSERT0(dataset_feature_count[f]);
                                        continue;
                                }
                                arr = dataset_feature_count;
                        }
                        if (feature_get_refcount(spa, &spa_feature_table[f],
                            &refcount) == ENOTSUP)
                                continue;
                        if (arr[f] != refcount) {
                                (void) printf("%s feature refcount mismatch: "
                                    "%lld consumers != %lld refcount\n",
                                    spa_feature_table[f].fi_uname,
                                    (longlong_t)arr[f], (longlong_t)refcount);
                                rc = 2;
                        } else {
                                (void) printf("Verified %s feature refcount "
                                    "of %llu is correct\n",
                                    spa_feature_table[f].fi_uname,
                                    (longlong_t)refcount);
                        }
                }

                if (rc == 0)
                        rc = verify_device_removal_feature_counts(spa);
        }

        if (rc == 0 && (dump_opt['b'] || dump_opt['c']))
                rc = dump_block_stats(spa);

        if (rc == 0)
                rc = verify_spacemap_refcounts(spa);

        if (dump_opt['s'])
                show_pool_stats(spa);

        if (dump_opt['h'])
                dump_history(spa);

        if (rc == 0)
                rc = verify_checkpoint(spa);

        if (rc != 0) {
                dump_debug_buffer();
                exit(rc);
        }
}

#define ZDB_FLAG_CHECKSUM       0x0001
#define ZDB_FLAG_DECOMPRESS     0x0002
#define ZDB_FLAG_BSWAP          0x0004
#define ZDB_FLAG_GBH            0x0008
#define ZDB_FLAG_INDIRECT       0x0010
#define ZDB_FLAG_RAW            0x0020
#define ZDB_FLAG_PRINT_BLKPTR   0x0040
#define ZDB_FLAG_VERBOSE        0x0080

static int flagbits[256];
static char flagbitstr[16];

static void
zdb_print_blkptr(const blkptr_t *bp, int flags)
{
        char blkbuf[BP_SPRINTF_LEN];

        if (flags & ZDB_FLAG_BSWAP)
                byteswap_uint64_array((void *)bp, sizeof (blkptr_t));

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

static void
zdb_dump_indirect(blkptr_t *bp, int nbps, int flags)
{
        int i;

        for (i = 0; i < nbps; i++)
                zdb_print_blkptr(&bp[i], flags);
}

static void
zdb_dump_gbh(void *buf, 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);
        VERIFY(write(fileno(stdout), buf, size) == size);
}

static void
zdb_dump_block(char *label, void *buf, uint64_t size, int flags)
{
        uint64_t *d = (uint64_t *)buf;
        unsigned nwords = size / sizeof (uint64_t);
        int do_bswap = !!(flags & ZDB_FLAG_BSWAP);
        unsigned i, j;
        const char *hdr;
        char *c;


        if (do_bswap)
                hdr = " 7 6 5 4 3 2 1 0   f e d c b a 9 8";
        else
                hdr = " 0 1 2 3 4 5 6 7   8 9 a b c d e f";

        (void) printf("\n%s\n%6s   %s  0123456789abcdef\n", label, "", hdr);

#ifdef _LITTLE_ENDIAN
        /* correct the endianness */
        do_bswap = !do_bswap;
#endif
        for (i = 0; i < nwords; i += 2) {
                (void) printf("%06llx:  %016llx  %016llx  ",
                    (u_longlong_t)(i * sizeof (uint64_t)),
                    (u_longlong_t)(do_bswap ? BSWAP_64(d[i]) : d[i]),
                    (u_longlong_t)(do_bswap ? BSWAP_64(d[i + 1]) : d[i + 1]));

                c = (char *)&d[i];
                for (j = 0; j < 2 * sizeof (uint64_t); j++)
                        (void) printf("%c", isprint(c[j]) ? c[j] : '.');
                (void) printf("\n");
        }
}

/*
 * There are two acceptable formats:
 *      leaf_name         - For example: c1t0d0 or /tmp/ztest.0a
 *      child[.child]*    - For example: 0.1.1
 *
 * The second form can be used to specify arbitrary vdevs anywhere
 * in the hierarchy.  For example, in a pool with a mirror of
 * RAID-Zs, you can specify either RAID-Z vdev with 0.0 or 0.1 .
 */
static vdev_t *
zdb_vdev_lookup(vdev_t *vdev, const char *path)
{
        char *s, *p, *q;
        unsigned i;

        if (vdev == NULL)
                return (NULL);

        /* First, assume the x.x.x.x format */
        i = strtoul(path, &s, 10);
        if (s == path || (s && *s != '.' && *s != '\0'))
                goto name;
        if (i >= vdev->vdev_children)
                return (NULL);

        vdev = vdev->vdev_child[i];
        if (s && *s == '\0')
                return (vdev);
        return (zdb_vdev_lookup(vdev, s+1));

name:
        for (i = 0; i < vdev->vdev_children; i++) {
                vdev_t *vc = vdev->vdev_child[i];

                if (vc->vdev_path == NULL) {
                        vc = zdb_vdev_lookup(vc, path);
                        if (vc == NULL)
                                continue;
                        else
                                return (vc);
                }

                p = strrchr(vc->vdev_path, '/');
                p = p ? p + 1 : vc->vdev_path;
                q = &vc->vdev_path[strlen(vc->vdev_path) - 2];

                if (strcmp(vc->vdev_path, path) == 0)
                        return (vc);
                if (strcmp(p, path) == 0)
                        return (vc);
                if (strcmp(q, "s0") == 0 && strncmp(p, path, q - p) == 0)
                        return (vc);
        }

        return (NULL);
}

static int
name_from_objset_id(spa_t *spa, uint64_t objset_id, char *outstr)
{
        dsl_dataset_t *ds;

        dsl_pool_config_enter(spa->spa_dsl_pool, FTAG);
        int error = dsl_dataset_hold_obj(spa->spa_dsl_pool, objset_id,
            NULL, &ds);
        if (error != 0) {
                (void) fprintf(stderr, "failed to hold objset %llu: %s\n",
                    (u_longlong_t)objset_id, strerror(error));
                dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
                return (error);
        }
        dsl_dataset_name(ds, outstr);
        dsl_dataset_rele(ds, NULL);
        dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
        return (0);
}

static boolean_t
zdb_parse_block_sizes(char *sizes, uint64_t *lsize, uint64_t *psize)
{
        char *s0, *s1, *tmp = NULL;

        if (sizes == NULL)
                return (B_FALSE);

        s0 = strtok_r(sizes, "/", &tmp);
        if (s0 == NULL)
                return (B_FALSE);
        s1 = strtok_r(NULL, "/", &tmp);
        *lsize = strtoull(s0, NULL, 16);
        *psize = s1 ? strtoull(s1, NULL, 16) : *lsize;
        return (*lsize >= *psize && *psize > 0);
}

#define ZIO_COMPRESS_MASK(alg)  (1ULL << (ZIO_COMPRESS_##alg))

static boolean_t
zdb_decompress_block(abd_t *pabd, void *buf, void *lbuf, uint64_t lsize,
    uint64_t psize, int flags)
{
        (void) buf;
        boolean_t exceeded = B_FALSE;
        /*
         * We don't know how the data was compressed, so just try
         * every decompress function at every inflated blocksize.
         */
        void *lbuf2 = umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL);
        int cfuncs[ZIO_COMPRESS_FUNCTIONS] = { 0 };
        int *cfuncp = cfuncs;
        uint64_t maxlsize = SPA_MAXBLOCKSIZE;
        uint64_t mask = ZIO_COMPRESS_MASK(ON) | ZIO_COMPRESS_MASK(OFF) |
            ZIO_COMPRESS_MASK(INHERIT) | ZIO_COMPRESS_MASK(EMPTY) |
            (getenv("ZDB_NO_ZLE") ? ZIO_COMPRESS_MASK(ZLE) : 0);
        *cfuncp++ = ZIO_COMPRESS_LZ4;
        *cfuncp++ = ZIO_COMPRESS_LZJB;
        mask |= ZIO_COMPRESS_MASK(LZ4) | ZIO_COMPRESS_MASK(LZJB);
        for (int c = 0; c < ZIO_COMPRESS_FUNCTIONS; c++)
                if (((1ULL << c) & mask) == 0)
                        *cfuncp++ = c;

        /*
         * On the one hand, with SPA_MAXBLOCKSIZE at 16MB, this
         * could take a while and we should let the user know
         * we are not stuck.  On the other hand, printing progress
         * info gets old after a while.  User can specify 'v' flag
         * to see the progression.
         */
        if (lsize == psize)
                lsize += SPA_MINBLOCKSIZE;
        else
                maxlsize = lsize;
        for (; lsize <= maxlsize; lsize += SPA_MINBLOCKSIZE) {
                for (cfuncp = cfuncs; *cfuncp; cfuncp++) {
                        if (flags & ZDB_FLAG_VERBOSE) {
                                (void) fprintf(stderr,
                                    "Trying %05llx -> %05llx (%s)\n",
                                    (u_longlong_t)psize,
                                    (u_longlong_t)lsize,
                                    zio_compress_table[*cfuncp].\
                                    ci_name);
                        }

                        /*
                         * We randomize lbuf2, and decompress to both
                         * lbuf and lbuf2. This way, we will know if
                         * decompression fill exactly to lsize.
                         */
                        VERIFY0(random_get_pseudo_bytes(lbuf2, lsize));

                        if (zio_decompress_data(*cfuncp, pabd,
                            lbuf, psize, lsize, NULL) == 0 &&
                            zio_decompress_data(*cfuncp, pabd,
                            lbuf2, psize, lsize, NULL) == 0 &&
                            memcmp(lbuf, lbuf2, lsize) == 0)
                                break;
                }
                if (*cfuncp != 0)
                        break;
        }
        umem_free(lbuf2, SPA_MAXBLOCKSIZE);

        if (lsize > maxlsize) {
                exceeded = B_TRUE;
        }
        if (*cfuncp == ZIO_COMPRESS_ZLE) {
                printf("\nZLE decompression was selected. If you "
                    "suspect the results are wrong,\ntry avoiding ZLE "
                    "by setting and exporting ZDB_NO_ZLE=\"true\"\n");
        }

        return (exceeded);
}

/*
 * Read a block from a pool and print it out.  The syntax of the
 * block descriptor is:
 *
 *      pool:vdev_specifier:offset:[lsize/]psize[:flags]
 *
 *      pool           - The name of the pool you wish to read from
 *      vdev_specifier - Which vdev (see comment for zdb_vdev_lookup)
 *      offset         - offset, in hex, in bytes
 *      size           - Amount of data to read, in hex, in bytes
 *      flags          - A string of characters specifying options
 *               b: Decode a blkptr at given offset within block
 *               c: Calculate and display checksums
 *               d: Decompress data before dumping
 *               e: Byteswap data before dumping
 *               g: Display data as a gang block header
 *               i: Display as an indirect block
 *               r: Dump raw data to stdout
 *               v: Verbose
 *
 */
static void
zdb_read_block(char *thing, spa_t *spa)
{
        blkptr_t blk, *bp = &blk;
        dva_t *dva = bp->blk_dva;
        int flags = 0;
        uint64_t offset = 0, psize = 0, lsize = 0, blkptr_offset = 0;
        zio_t *zio;
        vdev_t *vd;
        abd_t *pabd;
        void *lbuf, *buf;
        char *s, *p, *dup, *vdev, *flagstr, *sizes, *tmp = NULL;
        int i, error;
        boolean_t borrowed = B_FALSE, found = B_FALSE;

        dup = strdup(thing);
        s = strtok_r(dup, ":", &tmp);
        vdev = s ? s : "";
        s = strtok_r(NULL, ":", &tmp);
        offset = strtoull(s ? s : "", NULL, 16);
        sizes = strtok_r(NULL, ":", &tmp);
        s = strtok_r(NULL, ":", &tmp);
        flagstr = strdup(s ? s : "");

        s = NULL;
        tmp = NULL;
        if (!zdb_parse_block_sizes(sizes, &lsize, &psize))
                s = "invalid size(s)";
        if (!IS_P2ALIGNED(psize, DEV_BSIZE) || !IS_P2ALIGNED(lsize, 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);
                goto done;
        }

        for (s = strtok_r(flagstr, ":", &tmp);
            s != NULL;
            s = strtok_r(NULL, ":", &tmp)) {
                for (i = 0; i < strlen(flagstr); i++) {
                        int bit = flagbits[(uchar_t)flagstr[i]];

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

                        p = &flagstr[i + 1];
                        if (*p != ':' && *p != '\0') {
                                int j = 0, nextbit = flagbits[(uchar_t)*p];
                                char *end, offstr[8] = { 0 };
                                if ((bit == ZDB_FLAG_PRINT_BLKPTR) &&
                                    (nextbit == 0)) {
                                        /* look ahead to isolate the offset */
                                        while (nextbit == 0 &&
                                            strchr(flagbitstr, *p) == NULL) {
                                                offstr[j] = *p;
                                                j++;
                                                if (i + j > strlen(flagstr))
                                                        break;
                                                p++;
                                                nextbit = flagbits[(uchar_t)*p];
                                        }
                                        blkptr_offset = strtoull(offstr, &end,
                                            16);
                                        i += j;
                                } else if (nextbit == 0) {
                                        (void) printf("***Ignoring flag arg:"
                                            " '%c'\n", (uchar_t)*p);
                                }
                        }
                }
        }
        if (blkptr_offset % sizeof (blkptr_t)) {
                printf("Block pointer offset 0x%llx "
                    "must be divisible by 0x%x\n",
                    (longlong_t)blkptr_offset, (int)sizeof (blkptr_t));
                goto done;
        }
        if (found == B_FALSE && strlen(flagstr) > 0) {
                printf("Invalid flag arg: '%s'\n", flagstr);
                goto done;
        }

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

        pabd = abd_alloc_for_io(SPA_MAXBLOCKSIZE, B_FALSE);
        lbuf = umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL);

        BP_ZERO(bp);

        DVA_SET_VDEV(&dva[0], vd->vdev_id);
        DVA_SET_OFFSET(&dva[0], offset);
        DVA_SET_GANG(&dva[0], !!(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_PROPAGATE |
                    ZIO_FLAG_DONT_RETRY | ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW |
                    ZIO_FLAG_OPTIONAL, NULL, NULL));
        }

        error = zio_wait(zio);
        spa_config_exit(spa, SCL_STATE, FTAG);

        if (error) {
                (void) printf("Read of %s failed, error: %d\n", thing, error);
                goto out;
        }

        uint64_t orig_lsize = lsize;
        buf = lbuf;
        if (flags & ZDB_FLAG_DECOMPRESS) {
                boolean_t failed = zdb_decompress_block(pabd, buf, lbuf,
                    lsize, psize, flags);
                if (failed) {
                        (void) printf("Decompress of %s failed\n", thing);
                        goto out;
                }
        } else {
                buf = abd_borrow_buf_copy(pabd, lsize);
                borrowed = B_TRUE;
        }
        /*
         * Try to detect invalid block pointer.  If invalid, try
         * decompressing.
         */
        if ((flags & ZDB_FLAG_PRINT_BLKPTR || flags & ZDB_FLAG_INDIRECT) &&
            !(flags & ZDB_FLAG_DECOMPRESS)) {
                const blkptr_t *b = (const blkptr_t *)(void *)
                    ((uintptr_t)buf + (uintptr_t)blkptr_offset);
                if (zfs_blkptr_verify(spa, b, B_FALSE, BLK_VERIFY_ONLY) ==
                    B_FALSE) {
                        abd_return_buf_copy(pabd, buf, lsize);
                        borrowed = B_FALSE;
                        buf = lbuf;
                        boolean_t failed = zdb_decompress_block(pabd, buf,
                            lbuf, lsize, psize, flags);
                        b = (const blkptr_t *)(void *)
                            ((uintptr_t)buf + (uintptr_t)blkptr_offset);
                        if (failed || zfs_blkptr_verify(spa, b, B_FALSE,
                            BLK_VERIFY_LOG) == B_FALSE) {
                                printf("invalid block pointer at this DVA\n");
                                goto out;
                        }
                }
        }

        if (flags & ZDB_FLAG_PRINT_BLKPTR)
                zdb_print_blkptr((blkptr_t *)(void *)
                    ((uintptr_t)buf + (uintptr_t)blkptr_offset), flags);
        else if (flags & ZDB_FLAG_RAW)
                zdb_dump_block_raw(buf, lsize, flags);
        else if (flags & ZDB_FLAG_INDIRECT)
                zdb_dump_indirect((blkptr_t *)buf,
                    orig_lsize / sizeof (blkptr_t), flags);
        else if (flags & ZDB_FLAG_GBH)
                zdb_dump_gbh(buf, flags);
        else
                zdb_dump_block(thing, buf, lsize, flags);

        /*
         * If :c was specified, iterate through the checksum table to
         * calculate and display each checksum for our specified
         * DVA and length.
         */
        if ((flags & ZDB_FLAG_CHECKSUM) && !(flags & ZDB_FLAG_RAW) &&
            !(flags & ZDB_FLAG_GBH)) {
                zio_t *czio;
                (void) printf("\n");
                for (enum zio_checksum ck = ZIO_CHECKSUM_LABEL;
                    ck < ZIO_CHECKSUM_FUNCTIONS; ck++) {

                        if ((zio_checksum_table[ck].ci_flags &
                            ZCHECKSUM_FLAG_EMBEDDED) ||
                            ck == ZIO_CHECKSUM_NOPARITY) {
                                continue;
                        }
                        BP_SET_CHECKSUM(bp, ck);
                        spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
                        czio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
                        czio->io_bp = bp;

                        if (vd == vd->vdev_top) {
                                zio_nowait(zio_read(czio, spa, bp, pabd, psize,
                                    NULL, NULL,
                                    ZIO_PRIORITY_SYNC_READ,
                                    ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW |
                                    ZIO_FLAG_DONT_RETRY, NULL));
                        } else {
                                zio_nowait(zio_vdev_child_io(czio, bp, vd,
                                    offset, pabd, psize, ZIO_TYPE_READ,
                                    ZIO_PRIORITY_SYNC_READ,
                                    ZIO_FLAG_DONT_CACHE |
                                    ZIO_FLAG_DONT_PROPAGATE |
                                    ZIO_FLAG_DONT_RETRY |
                                    ZIO_FLAG_CANFAIL | ZIO_FLAG_RAW |
                                    ZIO_FLAG_SPECULATIVE |
                                    ZIO_FLAG_OPTIONAL, NULL, NULL));
                        }
                        error = zio_wait(czio);
                        if (error == 0 || error == ECKSUM) {
                                zio_t *ck_zio = zio_root(spa, NULL, NULL, 0);
                                ck_zio->io_offset =
                                    DVA_GET_OFFSET(&bp->blk_dva[0]);
                                ck_zio->io_bp = bp;
                                zio_checksum_compute(ck_zio, ck, pabd, lsize);
                                printf("%12s\tcksum=%llx:%llx:%llx:%llx\n",
                                    zio_checksum_table[ck].ci_name,
                                    (u_longlong_t)bp->blk_cksum.zc_word[0],
                                    (u_longlong_t)bp->blk_cksum.zc_word[1],
                                    (u_longlong_t)bp->blk_cksum.zc_word[2],
                                    (u_longlong_t)bp->blk_cksum.zc_word[3]);
                                zio_wait(ck_zio);
                        } else {
                                printf("error %d reading block\n", error);
                        }
                        spa_config_exit(spa, SCL_STATE, FTAG);
                }
        }

        if (borrowed)
                abd_return_buf_copy(pabd, buf, lsize);

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

static void
zdb_embedded_block(char *thing)
{
        blkptr_t bp = {{{{0}}}};
        unsigned long long *words = (void *)&bp;
        char *buf;
        int err;

        err = sscanf(thing, "%llx:%llx:%llx:%llx:%llx:%llx:%llx:%llx:"
            "%llx:%llx:%llx:%llx:%llx:%llx:%llx:%llx",
            words + 0, words + 1, words + 2, words + 3,
            words + 4, words + 5, words + 6, words + 7,
            words + 8, words + 9, words + 10, words + 11,
            words + 12, words + 13, words + 14, words + 15);
        if (err != 16) {
                (void) fprintf(stderr, "invalid input format\n");
                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);
                exit(1);
        }
        zdb_dump_block_raw(buf, BPE_GET_LSIZE(&bp), 0);
        free(buf);
}

/* check for valid hex or decimal numeric string */
static boolean_t
zdb_numeric(char *str)
{
        int i = 0;

        if (strlen(str) == 0)
                return (B_FALSE);
        if (strncmp(str, "0x", 2) == 0 || strncmp(str, "0X", 2) == 0)
                i = 2;
        for (; i < strlen(str); i++) {
                if (!isxdigit(str[i]))
                        return (B_FALSE);
        }
        return (B_TRUE);
}

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, *target_pool, dsname[ZFS_MAX_DATASET_NAME_LEN];
        nvlist_t *policy = NULL;
        uint64_t max_txg = UINT64_MAX;
        int64_t objset_id = -1;
        uint64_t object;
        int flags = ZFS_IMPORT_MISSING_LOG;
        int rewind = ZPOOL_NEVER_REWIND;
        char *spa_config_path_env, *objset_str;
        boolean_t target_is_spa = B_TRUE, dataset_lookup = B_FALSE;
        nvlist_t *cfg = NULL;

        (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;

        /*
         * For performance reasons, we set this tunable down. We do so before
         * the arg parsing section so that the user can override this value if
         * they choose.
         */
        zfs_btree_verify_intensity = 3;

        struct option long_options[] = {
                {"ignore-assertions",   no_argument,            NULL, 'A'},
                {"block-stats",         no_argument,            NULL, 'b'},
                {"checksum",            no_argument,            NULL, 'c'},
                {"config",              no_argument,            NULL, 'C'},
                {"datasets",            no_argument,            NULL, 'd'},
                {"dedup-stats",         no_argument,            NULL, 'D'},
                {"exported",            no_argument,            NULL, 'e'},
                {"embedded-block-pointer",      no_argument,    NULL, 'E'},
                {"automatic-rewind",    no_argument,            NULL, 'F'},
                {"dump-debug-msg",      no_argument,            NULL, 'G'},
                {"history",             no_argument,            NULL, 'h'},
                {"intent-logs",         no_argument,            NULL, 'i'},
                {"inflight",            required_argument,      NULL, 'I'},
                {"checkpointed-state",  no_argument,            NULL, 'k'},
                {"label",               no_argument,            NULL, 'l'},
                {"disable-leak-tracking",       no_argument,    NULL, 'L'},
                {"metaslabs",           no_argument,            NULL, 'm'},
                {"metaslab-groups",     no_argument,            NULL, 'M'},
                {"numeric",             no_argument,            NULL, 'N'},
                {"option",              required_argument,      NULL, 'o'},
                {"object-lookups",      no_argument,            NULL, 'O'},
                {"path",                required_argument,      NULL, 'p'},
                {"parseable",           no_argument,            NULL, 'P'},
                {"skip-label",          no_argument,            NULL, 'q'},
                {"copy-object",         no_argument,            NULL, 'r'},
                {"read-block",          no_argument,            NULL, 'R'},
                {"io-stats",            no_argument,            NULL, 's'},
                {"simulate-dedup",      no_argument,            NULL, 'S'},
                {"txg",                 required_argument,      NULL, 't'},
                {"uberblock",           no_argument,            NULL, 'u'},
                {"cachefile",           required_argument,      NULL, 'U'},
                {"verbose",             no_argument,            NULL, 'v'},
                {"verbatim",            no_argument,            NULL, 'V'},
                {"dump-blocks",         required_argument,      NULL, 'x'},
                {"extreme-rewind",      no_argument,            NULL, 'X'},
                {"all-reconstruction",  no_argument,            NULL, 'Y'},
                {"livelist",            no_argument,            NULL, 'y'},
                {"zstd-headers",        no_argument,            NULL, 'Z'},
                {0, 0, 0, 0}
        };

        while ((c = getopt_long(argc, argv,
            "AbcCdDeEFGhiI:klLmMNo:Op:PqrRsSt:uU:vVx:XYyZ",
            long_options, NULL)) != -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 'N':
                case 'O':
                case 'r':
                case 'R':
                case 's':
                case 'S':
                case 'u':
                case 'y':
                case 'Z':
                        dump_opt[c]++;
                        dump_all = 0;
                        break;
                case 'A':
                case 'e':
                case 'F':
                case 'k':
                case 'L':
                case 'P':
                case 'q':
                case 'X':
                        dump_opt[c]++;
                        break;
                case 'Y':
                        zfs_reconstruct_indirect_combinations_max = INT_MAX;
                        zfs_deadman_enabled = 0;
                        break;
                /* NB: Sort single match options below. */
                case 'I':
                        max_inflight_bytes = strtoull(optarg, NULL, 0);
                        if (max_inflight_bytes == 0) {
                                (void) fprintf(stderr, "maximum number "
                                    "of inflight bytes must be greater "
                                    "than 0\n");
                                usage();
                        }
                        break;
                case '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);
                                memcpy(tmp, searchdirs, nsearch *
                                    sizeof (char *));
                                umem_free(searchdirs,
                                    nsearch * sizeof (char *));
                                searchdirs = tmp;
                        }
                        searchdirs[nsearch++] = optarg;
                        break;
                case 't':
                        max_txg = strtoull(optarg, NULL, 0);
                        if (max_txg < TXG_INITIAL) {
                                (void) fprintf(stderr, "incorrect txg "
                                    "specified: %s\n", optarg);
                                usage();
                        }
                        break;
                case 'U':
                        spa_config_path = optarg;
                        if (spa_config_path[0] != '/') {
                                (void) fprintf(stderr,
                                    "cachefile must be an absolute path "
                                    "(i.e. start with a slash)\n");
                                usage();
                        }
                        break;
                case 'v':
                        verbose++;
                        break;
                case 'V':
                        flags = ZFS_IMPORT_VERBATIM;
                        break;
                case 'x':
                        vn_dumpdir = optarg;
                        break;
                default:
                        usage();
                        break;
                }
        }

        if (!dump_opt['e'] && searchdirs != NULL) {
                (void) fprintf(stderr, "-p option requires use of -e\n");
                usage();
        }
#if defined(_LP64)
        /*
         * ZDB does not typically re-read blocks; therefore limit the ARC
         * to 256 MB, which can be used entirely for metadata.
         */
        zfs_arc_min = zfs_arc_meta_min = 2ULL << SPA_MAXBLOCKSHIFT;
        zfs_arc_max = zfs_arc_meta_limit = 256 * 1024 * 1024;
#endif

        /*
         * "zdb -c" uses checksum-verifying scrub i/os which are async reads.
         * "zdb -b" uses traversal prefetch which uses async reads.
         * For good performance, let several of them be active at once.
         */
        zfs_vdev_async_read_max_active = 10;

        /*
         * Disable reference tracking for better performance.
         */
        reference_tracking_enable = B_FALSE;

        /*
         * Do not fail spa_load when spa_load_verify fails. This is needed
         * to load non-idle pools.
         */
        spa_load_verify_dryrun = B_TRUE;

        /*
         * ZDB should have ability to read spacemaps.
         */
        spa_mode_readable_spacemaps = B_TRUE;

        kernel_init(SPA_MODE_READ);

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

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

        libspl_set_assert_ok((dump_opt['A'] == 1) || (dump_opt['A'] > 2));
        zfs_recover = (dump_opt['A'] > 1);

        argc -= optind;
        argv += optind;
        if (argc < 2 && dump_opt['R'])
                usage();

        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], NULL));
        }
        if (dump_opt['r']) {
                target_is_spa = B_FALSE;
                if (argc != 3)
                        usage();
                dump_opt['v'] = verbose;
                error = dump_path(argv[0], argv[1], &object);
        }

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

        /* -N implies -d */
        if (dump_opt['N'] && dump_opt['d'] == 0)
                dump_opt['d'] = dump_opt['N'];

        if (nvlist_alloc(&policy, NV_UNIQUE_NAME_TYPE, 0) != 0 ||
            nvlist_add_uint64(policy, ZPOOL_LOAD_REQUEST_TXG, max_txg) != 0 ||
            nvlist_add_uint32(policy, ZPOOL_LOAD_REWIND_POLICY, rewind) != 0)
                fatal("internal error: %s", strerror(ENOMEM));

        error = 0;
        target = argv[0];

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

                target_pool = strdup(target);
                *strpbrk(target_pool, "/@") = '\0';

                target_is_spa = B_FALSE;
                targetlen = strlen(target);
                if (targetlen && target[targetlen - 1] == '/')
                        target[targetlen - 1] = '\0';

                /*
                 * See if an objset ID was supplied (-d <pool>/<objset ID>).
                 * To disambiguate tank/100, consider the 100 as objsetID
                 * if -N was given, otherwise 100 is an objsetID iff
                 * tank/100 as a named dataset fails on lookup.
                 */
                objset_str = strchr(target, '/');
                if (objset_str && strlen(objset_str) > 1 &&
                    zdb_numeric(objset_str + 1)) {
                        char *endptr;
                        errno = 0;
                        objset_str++;
                        objset_id = strtoull(objset_str, &endptr, 0);
                        /* dataset 0 is the same as opening the pool */
                        if (errno == 0 && endptr != objset_str &&
                            objset_id != 0) {
                                if (dump_opt['N'])
                                        dataset_lookup = B_TRUE;
                        }
                        /* normal dataset name not an objset ID */
                        if (endptr == objset_str) {
                                objset_id = -1;
                        }
                } else if (objset_str && !zdb_numeric(objset_str + 1) &&
                    dump_opt['N']) {
                        printf("Supply a numeric objset ID with -N\n");
                        exit(1);
                }
        } else {
                target_pool = target;
        }

        if (dump_opt['e']) {
                importargs_t args = { 0 };

                args.paths = nsearch;
                args.path = searchdirs;
                args.can_be_active = B_TRUE;

                error = zpool_find_config(NULL, target_pool, &cfg, &args,
                    &libzpool_config_ops);

                if (error == 0) {

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

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

                        /*
                         * Disable the activity check to allow examination of
                         * active pools.
                         */
                        error = spa_import(target_pool, cfg, NULL,
                            flags | ZFS_IMPORT_SKIP_MMP);
                }
        }

        if (searchdirs != NULL) {
                umem_free(searchdirs, nsearch * sizeof (char *));
                searchdirs = NULL;
        }

        /*
         * import_checkpointed_state makes the assumption that the
         * target pool that we pass it is already part of the spa
         * namespace. Because of that we need to make sure to call
         * it always after the -e option has been processed, which
         * imports the pool to the namespace if it's not in the
         * cachefile.
         */
        char *checkpoint_pool = NULL;
        char *checkpoint_target = NULL;
        if (dump_opt['k']) {
                checkpoint_pool = import_checkpointed_state(target, cfg,
                    &checkpoint_target);

                if (checkpoint_target != NULL)
                        target = checkpoint_target;
        }

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

        if (target_pool != target)
                free(target_pool);

        if (error == 0) {
                if (dump_opt['k'] && (target_is_spa || dump_opt['R'])) {
                        ASSERT(checkpoint_pool != NULL);
                        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'] || objset_id == 0) {
                        zdb_set_skip_mmp(target);
                        error = spa_open_rewind(target, &spa, FTAG, policy,
                            NULL);
                        if (error) {
                                /*
                                 * If we're missing the log device then
                                 * try opening the pool after clearing the
                                 * log state.
                                 */
                                mutex_enter(&spa_namespace_lock);
                                if ((spa = spa_lookup(target)) != NULL &&
                                    spa->spa_log_state == SPA_LOG_MISSING) {
                                        spa->spa_log_state = SPA_LOG_CLEAR;
                                        error = 0;
                                }
                                mutex_exit(&spa_namespace_lock);

                                if (!error) {
                                        error = spa_open_rewind(target, &spa,
                                            FTAG, policy, NULL);
                                }
                        }
                } else if (strpbrk(target, "#") != NULL) {
                        dsl_pool_t *dp;
                        error = dsl_pool_hold(target, FTAG, &dp);
                        if (error != 0) {
                                fatal("can't dump '%s': %s", target,
                                    strerror(error));
                        }
                        error = dump_bookmark(dp, target, B_TRUE, verbose > 1);
                        dsl_pool_rele(dp, FTAG);
                        if (error != 0) {
                                fatal("can't dump '%s': %s", target,
                                    strerror(error));
                        }
                        return (error);
                } else {
                        target_pool = strdup(target);
                        if (strpbrk(target, "/@") != NULL)
                                *strpbrk(target_pool, "/@") = '\0';

                        zdb_set_skip_mmp(target);
                        /*
                         * If -N was supplied, the user has indicated that
                         * zdb -d <pool>/<objsetID> is in effect.  Otherwise
                         * we first assume that the dataset string is the
                         * dataset name.  If dmu_objset_hold fails with the
                         * dataset string, and we have an objset_id, retry the
                         * lookup with the objsetID.
                         */
                        boolean_t retry = B_TRUE;
retry_lookup:
                        if (dataset_lookup == B_TRUE) {
                                /*
                                 * Use the supplied id to get the name
                                 * for open_objset.
                                 */
                                error = spa_open(target_pool, &spa, FTAG);
                                if (error == 0) {
                                        error = name_from_objset_id(spa,
                                            objset_id, dsname);
                                        spa_close(spa, FTAG);
                                        if (error == 0)
                                                target = dsname;
                                }
                        }
                        if (error == 0) {
                                if (objset_id > 0 && retry) {
                                        int err = dmu_objset_hold(target, FTAG,
                                            &os);
                                        if (err) {
                                                dataset_lookup = B_TRUE;
                                                retry = B_FALSE;
                                                goto retry_lookup;
                                        } else {
                                                dmu_objset_rele(os, FTAG);
                                        }
                                }
                                error = open_objset(target, FTAG, &os);
                        }
                        if (error == 0)
                                spa = dmu_objset_spa(os);
                        free(target_pool);
                }
        }
        nvlist_free(policy);

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

        /*
         * Set the pool failure mode to panic in order to prevent the pool
         * from suspending.  A suspended I/O will have no way to resume and
         * can prevent the zdb(8) command from terminating as expected.
         */
        if (spa != NULL)
                spa->spa_failmode = ZIO_FAILURE_MODE_PANIC;

        argv++;
        argc--;
        if (dump_opt['r']) {
                error = zdb_copy_object(os, object, argv[1]);
        } else if (!dump_opt['R']) {
                flagbits['d'] = ZOR_FLAG_DIRECTORY;
                flagbits['f'] = ZOR_FLAG_PLAIN_FILE;
                flagbits['m'] = ZOR_FLAG_SPACE_MAP;
                flagbits['z'] = ZOR_FLAG_ZAP;
                flagbits['A'] = ZOR_FLAG_ALL_TYPES;

                if (argc > 0 && dump_opt['d']) {
                        zopt_object_args = argc;
                        zopt_object_ranges = calloc(zopt_object_args,
                            sizeof (zopt_object_range_t));
                        for (unsigned i = 0; i < zopt_object_args; i++) {
                                int err;
                                char *msg = NULL;

                                err = parse_object_range(argv[i],
                                    &zopt_object_ranges[i], &msg);
                                if (err != 0)
                                        fatal("Bad object or range: '%s': %s\n",
                                            argv[i], msg ? msg : "");
                        }
                } else if (argc > 0 && dump_opt['m']) {
                        zopt_metaslab_args = argc;
                        zopt_metaslab = calloc(zopt_metaslab_args,
                            sizeof (uint64_t));
                        for (unsigned i = 0; i < zopt_metaslab_args; i++) {
                                errno = 0;
                                zopt_metaslab[i] = strtoull(argv[i], NULL, 0);
                                if (zopt_metaslab[i] == 0 && errno != 0)
                                        fatal("bad number %s: %s", argv[i],
                                            strerror(errno));
                        }
                }
                if (os != NULL) {
                        dump_objset(os);
                } else if (zopt_object_args > 0 && !dump_opt['m']) {
                        dump_objset(spa->spa_meta_objset);
                } else {
                        dump_zpool(spa);
                }
        } else {
                flagbits['b'] = ZDB_FLAG_PRINT_BLKPTR;
                flagbits['c'] = ZDB_FLAG_CHECKSUM;
                flagbits['d'] = ZDB_FLAG_DECOMPRESS;
                flagbits['e'] = ZDB_FLAG_BSWAP;
                flagbits['g'] = ZDB_FLAG_GBH;
                flagbits['i'] = ZDB_FLAG_INDIRECT;
                flagbits['r'] = ZDB_FLAG_RAW;
                flagbits['v'] = ZDB_FLAG_VERBOSE;

                for (int i = 0; i < argc; i++)
                        zdb_read_block(argv[i], spa);
        }

        if (dump_opt['k']) {
                free(checkpoint_pool);
                if (!target_is_spa)
                        free(checkpoint_target);
        }

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

        fuid_table_destroy();

        dump_debug_buffer();

        kernel_fini();

        return (error);
}