cmd/zdb/zdb.c

	zdb.c revision c25056de36a33f2a76f79dcf64593f731d258013
/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/dmu.h>
#include <sys/zap.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_znode.h>
#include <sys/vdev.h>
#include <sys/vdev_impl.h>
#include <sys/metaslab_impl.h>
#include <sys/dmu_objset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_pool.h>
#include <sys/dbuf.h>
#include <sys/zil.h>
#include <sys/zil_impl.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <sys/dmu_traverse.h>
#include <sys/zio_checksum.h>
#include <sys/zio_compress.h>
#undef ZFS_MAXNAMELEN
#undef verify
#include <libzfs.h>

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

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

extern void dump_intent_log(zilog_t *);
uint64_t *zopt_object = NULL;
int zopt_objects = 0;
int zdb_advance = ADVANCE_PRE;
zbookmark_t zdb_noread = { 0, 0, ZB_NO_LEVEL, 0 };
libzfs_handle_t *g_zfs;

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

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

static void
usage(void)
{
    (void) fprintf(stderr,
        "Usage: %s [-udibcsvLUe] [-O order] [-B os:obj:level:blkid] "
        "dataset [object...]\n"
        "       %s -C [pool]\n"
        "       %s -l dev\n"
        "       %s -R vdev:offset:size:flags\n"
        "       %s [-p path_to_vdev_dir]\n",
        cmdname, cmdname, cmdname, cmdname, cmdname);

    (void) fprintf(stderr, "    -u uberblock\n");
    (void) fprintf(stderr, "    -d datasets\n");
    (void) fprintf(stderr, "        -C cached pool configuration\n");
    (void) fprintf(stderr, "    -i intent logs\n");
    (void) fprintf(stderr, "    -b block statistics\n");
    (void) fprintf(stderr, "    -c checksum all data blocks\n");
    (void) fprintf(stderr, "    -s report stats on zdb's I/O\n");
    (void) fprintf(stderr, "    -v verbose (applies to all others)\n");
    (void) fprintf(stderr, "        -l dump label contents\n");
    (void) fprintf(stderr, "    -L live pool (allows some errors)\n");
    (void) fprintf(stderr, "    -O [!]<pre|post|prune|data|holes> "
        "visitation order\n");
    (void) fprintf(stderr, "    -U use zpool.cache in /tmp\n");
    (void) fprintf(stderr, "    -B objset:object:level:blkid -- "
        "simulate bad block\n");
    (void) fprintf(stderr, "        -R read and display block from a"
        "device\n");
    (void) fprintf(stderr, "        -e Pool is exported/destroyed\n");
    (void) fprintf(stderr, "    -p <Path to vdev dir> (use with -e)\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
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");

    exit(1);
}

static void
dump_nvlist(nvlist_t *list, int indent)
{
    nvpair_t *elem = NULL;

    while ((elem = nvlist_next_nvpair(list, elem)) != NULL) {
        switch (nvpair_type(elem)) {
        case DATA_TYPE_STRING:
            {
                char *value;

                VERIFY(nvpair_value_string(elem, &value) == 0);
                (void) printf("%*s%s='%s'\n", indent, "",
                    nvpair_name(elem), value);
            }
            break;

        case DATA_TYPE_UINT64:
            {
                uint64_t value;

                VERIFY(nvpair_value_uint64(elem, &value) == 0);
                (void) printf("%*s%s=%llu\n", indent, "",
                    nvpair_name(elem), (u_longlong_t)value);
            }
            break;

        case DATA_TYPE_NVLIST:
            {
                nvlist_t *value;

                VERIFY(nvpair_value_nvlist(elem, &value) == 0);
                (void) printf("%*s%s\n", indent, "",
                    nvpair_name(elem));
                dump_nvlist(value, indent + 4);
            }
            break;

        case DATA_TYPE_NVLIST_ARRAY:
            {
                nvlist_t **value;
                uint_t c, count;

                VERIFY(nvpair_value_nvlist_array(elem, &value,
                    &count) == 0);

                for (c = 0; c < count; c++) {
                    (void) printf("%*s%s[%u]\n", indent, "",
                        nvpair_name(elem), c);
                    dump_nvlist(value[c], indent + 8);
                }
            }
            break;

        default:

            (void) printf("bad config type %d for %s\n",
                nvpair_type(elem), nvpair_name(elem));
        }
    }
}

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

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

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

    umem_free(packed, nvsize);

    dump_nvlist(nv, 8);

    nvlist_free(nv);
}

const char dump_zap_stars[] = "****************************************";
const int dump_zap_width = sizeof (dump_zap_stars) - 1;

static void
dump_zap_histogram(uint64_t histo[ZAP_HISTOGRAM_SIZE])
{
    int i;
    int minidx = ZAP_HISTOGRAM_SIZE - 1;
    int maxidx = 0;
    uint64_t max = 0;

    for (i = 0; i < ZAP_HISTOGRAM_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 < dump_zap_width)
        max = dump_zap_width;

    for (i = minidx; i <= maxidx; i++)
        (void) printf("\t\t\t%u: %6llu %s\n", i, (u_longlong_t)histo[i],
            &dump_zap_stars[(max - histo[i]) * dump_zap_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_zap_histogram(zs.zs_leafs_with_2n_pointers);

    (void) printf("\t\tBlocks with n*5 entries:\n");
    dump_zap_histogram(zs.zs_blocks_with_n5_entries);

    (void) printf("\t\tBlocks n/10 full:\n");
    dump_zap_histogram(zs.zs_blocks_n_tenths_full);

    (void) printf("\t\tEntries with n chunks:\n");
    dump_zap_histogram(zs.zs_entries_using_n_chunks);

    (void) printf("\t\tBuckets with n entries:\n");
    dump_zap_histogram(zs.zs_buckets_with_n_entries);
}

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

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

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

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

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

    for (zap_cursor_init(&zc, os, object);
        zap_cursor_retrieve(&zc, &attr) == 0;
        zap_cursor_advance(&zc)) {
        (void) printf("\t\t%s = ", attr.za_name);
        if (attr.za_num_integers == 0) {
            (void) printf("\n");
            continue;
        }
        prop = umem_zalloc(attr.za_num_integers *
            attr.za_integer_length, UMEM_NOFAIL);
        (void) zap_lookup(os, object, attr.za_name,
            attr.za_integer_length, attr.za_num_integers, prop);
        if (attr.za_integer_length == 1) {
            (void) printf("%s", (char *)prop);
        } else {
            for (i = 0; i < attr.za_num_integers; i++) {
                switch (attr.za_integer_length) {
                case 2:
                    (void) printf("%u ",
                        ((uint16_t *)prop)[i]);
                    break;
                case 4:
                    (void) printf("%u ",
                        ((uint32_t *)prop)[i]);
                    break;
                case 8:
                    (void) printf("%lld ",
                        (u_longlong_t)((int64_t *)prop)[i]);
                    break;
                }
            }
        }
        (void) printf("\n");
        umem_free(prop, attr.za_num_integers * attr.za_integer_length);
    }
    zap_cursor_fini(&zc);
}

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

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

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

static void
dump_spacemap(objset_t *os, space_map_obj_t *smo, space_map_t *sm)
{
    uint64_t alloc, offset, entry;
    uint8_t mapshift = sm->sm_shift;
    uint64_t mapstart = sm->sm_start;
    char *ddata[] = { "ALLOC", "FREE", "CONDENSE", "INVALID",
                "INVALID", "INVALID", "INVALID", "INVALID" };

    if (smo->smo_object == 0)
        return;

    /*
     * Print out the freelist entries in both encoded and decoded form.
     */
    alloc = 0;
    for (offset = 0; offset < smo->smo_objsize; offset += sizeof (entry)) {
        VERIFY(0 == dmu_read(os, smo->smo_object, offset,
            sizeof (entry), &entry));
        if (SM_DEBUG_DECODE(entry)) {
            (void) printf("\t\t[%4llu] %s: txg %llu, pass %llu\n",
                (u_longlong_t)(offset / sizeof (entry)),
                ddata[SM_DEBUG_ACTION_DECODE(entry)],
                (u_longlong_t)SM_DEBUG_TXG_DECODE(entry),
                (u_longlong_t)SM_DEBUG_SYNCPASS_DECODE(entry));
        } else {
            (void) printf("\t\t[%4llu]    %c  range:"
                " %08llx-%08llx  size: %06llx\n",
                (u_longlong_t)(offset / sizeof (entry)),
                SM_TYPE_DECODE(entry) == SM_ALLOC ? 'A' : 'F',
                (u_longlong_t)((SM_OFFSET_DECODE(entry) <<
                mapshift) + mapstart),
                (u_longlong_t)((SM_OFFSET_DECODE(entry) <<
                mapshift) + mapstart + (SM_RUN_DECODE(entry) <<
                mapshift)),
                (u_longlong_t)(SM_RUN_DECODE(entry) << mapshift));
            if (SM_TYPE_DECODE(entry) == SM_ALLOC)
                alloc += SM_RUN_DECODE(entry) << mapshift;
            else
                alloc -= SM_RUN_DECODE(entry) << mapshift;
        }
    }
    if (alloc != smo->smo_alloc) {
        (void) printf("space_map_object alloc (%llu) INCONSISTENT "
            "with space map summary (%llu)\n",
            (u_longlong_t)smo->smo_alloc, (u_longlong_t)alloc);
    }
}

static void
dump_metaslab(metaslab_t *msp)
{
    char freebuf[5];
    space_map_obj_t *smo = &msp->ms_smo;
    vdev_t *vd = msp->ms_group->mg_vd;
    spa_t *spa = vd->vdev_spa;

    nicenum(msp->ms_map.sm_size - smo->smo_alloc, freebuf);

    if (dump_opt['d'] <= 5) {
        (void) printf("\t%10llx   %10llu   %5s\n",
            (u_longlong_t)msp->ms_map.sm_start,
            (u_longlong_t)smo->smo_object,
            freebuf);
        return;
    }

    (void) printf(
        "\tvdev %llu   offset %08llx   spacemap %4llu   free %5s\n",
        (u_longlong_t)vd->vdev_id, (u_longlong_t)msp->ms_map.sm_start,
        (u_longlong_t)smo->smo_object, freebuf);

    ASSERT(msp->ms_map.sm_size == (1ULL << vd->vdev_ms_shift));

    dump_spacemap(spa->spa_meta_objset, smo, &msp->ms_map);
}

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

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

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

        spa_config_enter(spa, RW_READER, FTAG);
        (void) printf("\n    vdev %llu = %s\n\n",
            (u_longlong_t)vd->vdev_id, vdev_description(vd));
        spa_config_exit(spa, FTAG);

        if (dump_opt['d'] <= 5) {
            (void) printf("\t%10s   %10s   %5s\n",
                "offset", "spacemap", "free");
            (void) printf("\t%10s   %10s   %5s\n",
                "------", "--------", "----");
        }
        for (m = 0; m < vd->vdev_ms_count; m++)
            dump_metaslab(vd->vdev_ms[m]);
        (void) printf("\n");
    }
}

static void
dump_dtl(vdev_t *vd, int indent)
{
    avl_tree_t *t = &vd->vdev_dtl_map.sm_root;
    spa_t *spa = vd->vdev_spa;
    space_seg_t *ss;
    vdev_t *pvd;
    int c;

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

    spa_config_enter(spa, RW_READER, FTAG);
    (void) printf("\t%*s%s\n", indent, "", vdev_description(vd));
    spa_config_exit(spa, FTAG);

    for (ss = avl_first(t); ss; ss = AVL_NEXT(t, ss)) {
        /*
         * Everything in this DTL must appear in all parent DTL unions.
         */
        for (pvd = vd; pvd; pvd = pvd->vdev_parent)
            ASSERT(vdev_dtl_contains(&pvd->vdev_dtl_map,
                ss->ss_start, ss->ss_end - ss->ss_start));
        (void) printf("\t%*soutage [%llu,%llu] length %llu\n",
            indent, "",
            (u_longlong_t)ss->ss_start,
            (u_longlong_t)ss->ss_end - 1,
            (u_longlong_t)(ss->ss_end - ss->ss_start));
    }

    (void) printf("\n");

    if (dump_opt['d'] > 5 && vd->vdev_children == 0) {
        dump_spacemap(vd->vdev_spa->spa_meta_objset, &vd->vdev_dtl,
            &vd->vdev_dtl_map);
        (void) printf("\n");
    }

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

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

static uint64_t
blkid2offset(dnode_phys_t *dnp, int level, uint64_t blkid)
{
    if (level < 0)
        return (blkid);

    return ((blkid << (level * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT))) *
        dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
}

static void
sprintf_blkptr_compact(char *blkbuf, blkptr_t *bp, int alldvas)
{
    dva_t *dva = bp->blk_dva;
    int ndvas = alldvas ? BP_GET_NDVAS(bp) : 1;
    int i;

    blkbuf[0] = '\0';

    for (i = 0; i < ndvas; i++)
        (void) sprintf(blkbuf + 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]));

    (void) sprintf(blkbuf + strlen(blkbuf), "%llxL/%llxP F=%llu B=%llu",
        (u_longlong_t)BP_GET_LSIZE(bp),
        (u_longlong_t)BP_GET_PSIZE(bp),
        (u_longlong_t)bp->blk_fill,
        (u_longlong_t)bp->blk_birth);
}

/* ARGSUSED */
static int
zdb_indirect_cb(traverse_blk_cache_t *bc, spa_t *spa, void *a)
{
    zbookmark_t *zb = &bc->bc_bookmark;
    blkptr_t *bp = &bc->bc_blkptr;
    void *data = bc->bc_data;
    dnode_phys_t *dnp = bc->bc_dnode;
    char blkbuf[BP_SPRINTF_LEN + 80];
    int l;

    if (bc->bc_errno) {
        (void) sprintf(blkbuf,
            "Error %d reading <%llu, %llu, %lld, %llu>: ",
            bc->bc_errno,
            (u_longlong_t)zb->zb_objset,
            (u_longlong_t)zb->zb_object,
            (u_longlong_t)zb->zb_level,
            (u_longlong_t)zb->zb_blkid);
        goto out;
    }

    if (zb->zb_level == -1) {
        ASSERT3U(BP_GET_TYPE(bp), ==, DMU_OT_OBJSET);
        ASSERT3U(BP_GET_LEVEL(bp), ==, 0);
    } else {
        ASSERT3U(BP_GET_TYPE(bp), ==, dnp->dn_type);
        ASSERT3U(BP_GET_LEVEL(bp), ==, zb->zb_level);
    }

    if (zb->zb_level > 0) {
        uint64_t fill = 0;
        blkptr_t *bpx, *bpend;

        for (bpx = data, bpend = bpx + BP_GET_LSIZE(bp) / sizeof (*bpx);
            bpx < bpend; bpx++) {
            if (bpx->blk_birth != 0) {
                fill += bpx->blk_fill;
            } else {
                ASSERT(bpx->blk_fill == 0);
            }
        }
        ASSERT3U(fill, ==, bp->blk_fill);
    }

    if (zb->zb_level == 0 && dnp->dn_type == DMU_OT_DNODE) {
        uint64_t fill = 0;
        dnode_phys_t *dnx, *dnend;

        for (dnx = data, dnend = dnx + (BP_GET_LSIZE(bp)>>DNODE_SHIFT);
            dnx < dnend; dnx++) {
            if (dnx->dn_type != DMU_OT_NONE)
                fill++;
        }
        ASSERT3U(fill, ==, bp->blk_fill);
    }

    (void) sprintf(blkbuf, "%16llx ",
        (u_longlong_t)blkid2offset(dnp, zb->zb_level, zb->zb_blkid));

    ASSERT(zb->zb_level >= 0);

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

out:
    if (bp->blk_birth == 0) {
        (void) sprintf(blkbuf + strlen(blkbuf), "<hole>");
        (void) printf("%s\n", blkbuf);
    } else {
        sprintf_blkptr_compact(blkbuf + strlen(blkbuf), bp,
            dump_opt['d'] > 5 ? 1 : 0);
        (void) printf("%s\n", blkbuf);
    }

    return (bc->bc_errno ? ERESTART : 0);
}

/*ARGSUSED*/
static void
dump_indirect(objset_t *os, uint64_t object, void *data, size_t size)
{
    traverse_handle_t *th;
    uint64_t objset = dmu_objset_id(os);
    int advance = zdb_advance;

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

    if (object == 0)
        advance |= ADVANCE_DATA;

    th = traverse_init(dmu_objset_spa(os), zdb_indirect_cb, NULL, advance,
        ZIO_FLAG_CANFAIL);
    th->th_noread = zdb_noread;

    traverse_add_dnode(th, 0, -1ULL, objset, object);

    while (traverse_more(th) == EAGAIN)
        continue;

    (void) printf("\n");

    traverse_fini(th);
}

/*ARGSUSED*/
static void
dump_dsl_dir(objset_t *os, uint64_t object, void *data, size_t size)
{
    dsl_dir_phys_t *dd = data;
    time_t crtime;
    char used[6], compressed[6], uncompressed[6], quota[6], resv[6];

    if (dd == NULL)
        return;

    ASSERT(size == sizeof (*dd));

    crtime = dd->dd_creation_time;
    nicenum(dd->dd_used_bytes, used);
    nicenum(dd->dd_compressed_bytes, compressed);
    nicenum(dd->dd_uncompressed_bytes, uncompressed);
    nicenum(dd->dd_quota, quota);
    nicenum(dd->dd_reserved, resv);

    (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\tclone_parent_obj = %llu\n",
        (u_longlong_t)dd->dd_clone_parent_obj);
    (void) printf("\t\tchild_dir_zapobj = %llu\n",
        (u_longlong_t)dd->dd_child_dir_zapobj);
    (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\tquota = %s\n", quota);
    (void) printf("\t\treserved = %s\n", resv);
    (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);
}

/*ARGSUSED*/
static void
dump_dsl_dataset(objset_t *os, uint64_t object, void *data, size_t size)
{
    dsl_dataset_phys_t *ds = data;
    time_t crtime;
    char used[6], compressed[6], uncompressed[6], unique[6];
    char blkbuf[BP_SPRINTF_LEN];

    if (ds == NULL)
        return;

    ASSERT(size == sizeof (*ds));
    crtime = ds->ds_creation_time;
    nicenum(ds->ds_used_bytes, used);
    nicenum(ds->ds_compressed_bytes, compressed);
    nicenum(ds->ds_uncompressed_bytes, uncompressed);
    nicenum(ds->ds_unique_bytes, unique);
    sprintf_blkptr(blkbuf, BP_SPRINTF_LEN, &ds->ds_bp);

    (void) printf("\t\tdataset_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\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\tbp = %s\n", blkbuf);
}

static void
dump_bplist(objset_t *mos, uint64_t object, char *name)
{
    bplist_t bpl = { 0 };
    blkptr_t blk, *bp = &blk;
    uint64_t itor = 0;
    char bytes[6];
    char comp[6];
    char uncomp[6];

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

    mutex_init(&bpl.bpl_lock, NULL, MUTEX_DEFAULT, NULL);
    VERIFY(0 == bplist_open(&bpl, mos, object));
    if (bplist_empty(&bpl)) {
        bplist_close(&bpl);
        mutex_destroy(&bpl.bpl_lock);
        return;
    }

    nicenum(bpl.bpl_phys->bpl_bytes, bytes);
    if (bpl.bpl_dbuf->db_size == sizeof (bplist_phys_t)) {
        nicenum(bpl.bpl_phys->bpl_comp, comp);
        nicenum(bpl.bpl_phys->bpl_uncomp, uncomp);
        (void) printf("\n    %s: %llu entries, %s (%s/%s comp)\n",
            name, (u_longlong_t)bpl.bpl_phys->bpl_entries,
            bytes, comp, uncomp);
    } else {
        (void) printf("\n    %s: %llu entries, %s\n",
            name, (u_longlong_t)bpl.bpl_phys->bpl_entries, bytes);
    }

    if (dump_opt['d'] < 5) {
        bplist_close(&bpl);
        mutex_destroy(&bpl.bpl_lock);
        return;
    }

    (void) printf("\n");

    while (bplist_iterate(&bpl, &itor, bp) == 0) {
        char blkbuf[BP_SPRINTF_LEN];

        ASSERT(bp->blk_birth != 0);
        sprintf_blkptr_compact(blkbuf, bp, dump_opt['d'] > 5 ? 1 : 0);
        (void) printf("\tItem %3llu: %s\n",
            (u_longlong_t)itor - 1, blkbuf);
    }

    bplist_close(&bpl);
    mutex_destroy(&bpl.bpl_lock);
}

/*ARGSUSED*/
static void
dump_znode(objset_t *os, uint64_t object, void *data, size_t size)
{
    znode_phys_t *zp = data;
    time_t z_crtime, z_atime, z_mtime, z_ctime;
    char path[MAXPATHLEN * 2];  /* allow for xattr and failure prefix */
    int error;

    ASSERT(size >= sizeof (znode_phys_t));

    error = zfs_obj_to_path(os, object, path, sizeof (path));
    if (error != 0) {
        (void) snprintf(path, sizeof (path), "\?\?\?<object#%llu>",
            (u_longlong_t)object);
    }

    if (dump_opt['d'] < 3) {
        (void) printf("\t%s\n", path);
        return;
    }

    z_crtime = (time_t)zp->zp_crtime[0];
    z_atime = (time_t)zp->zp_atime[0];
    z_mtime = (time_t)zp->zp_mtime[0];
    z_ctime = (time_t)zp->zp_ctime[0];

    (void) printf("\tpath   %s\n", path);
    (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)zp->zp_gen);
    (void) printf("\tmode   %llo\n", (u_longlong_t)zp->zp_mode);
    (void) printf("\tsize   %llu\n", (u_longlong_t)zp->zp_size);
    (void) printf("\tparent %llu\n", (u_longlong_t)zp->zp_parent);
    (void) printf("\tlinks  %llu\n", (u_longlong_t)zp->zp_links);
    (void) printf("\txattr  %llu\n", (u_longlong_t)zp->zp_xattr);
    (void) printf("\trdev   0x%016llx\n", (u_longlong_t)zp->zp_rdev);
}

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

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

static object_viewer_t *object_viewer[DMU_OT_NUMTYPES] = {
    dump_none,      /* unallocated          */
    dump_zap,       /* object directory     */
    dump_uint64,        /* object array         */
    dump_none,      /* packed nvlist        */
    dump_packed_nvlist, /* packed nvlist size       */
    dump_none,      /* bplist           */
    dump_none,      /* bplist 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 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_uint64,        /* SPA history offsets      */
    dump_zap,       /* Pool properties      */
    dump_zap,       /* DSL permissions      */
};

static void
dump_object(objset_t *os, uint64_t object, int verbosity, int *print_header)
{
    dmu_buf_t *db = NULL;
    dmu_object_info_t doi;
    dnode_t *dn;
    void *bonus = NULL;
    size_t bsize = 0;
    char iblk[6], dblk[6], lsize[6], asize[6], bonus_size[6], segsize[6];
    char aux[50];
    int error;

    if (*print_header) {
        (void) printf("\n    Object  lvl   iblk   dblk  lsize"
            "  asize  type\n");
        *print_header = 0;
    }

    if (object == 0) {
        dn = os->os->os_meta_dnode;
    } 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 = ((dmu_buf_impl_t *)db)->db_dnode;
    }
    dmu_object_info_from_dnode(dn, &doi);

    nicenum(doi.doi_metadata_block_size, iblk);
    nicenum(doi.doi_data_block_size, dblk);
    nicenum(doi.doi_data_block_size * (doi.doi_max_block_offset + 1),
        lsize);
    nicenum(doi.doi_physical_blks << 9, asize);
    nicenum(doi.doi_bonus_size, bonus_size);

    aux[0] = '\0';

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

    if (doi.doi_compress != ZIO_COMPRESS_INHERIT || verbosity >= 6) {
        (void) snprintf(aux + strlen(aux), sizeof (aux), " (Z=%s)",
            zio_compress_table[doi.doi_compress].ci_name);
    }

    (void) printf("%10lld  %3u  %5s  %5s  %5s  %5s  %s%s\n",
        (u_longlong_t)object, doi.doi_indirection, iblk, dblk, lsize,
        asize, dmu_ot[doi.doi_type].ot_name, aux);

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

    if (verbosity >= 4) {
        object_viewer[doi.doi_bonus_type](os, object, bonus, bsize);
        object_viewer[doi.doi_type](os, object, NULL, 0);
        *print_header = 1;
    }

    if (verbosity >= 5)
        dump_indirect(os, object, NULL, 0);

    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 (;;) {
            error = dnode_next_offset(dn, B_FALSE, &start, minlvl,
                blkfill, 0);
            if (error)
                break;
            end = start;
            error = dnode_next_offset(dn, B_TRUE, &end, minlvl,
                blkfill, 0);
            nicenum(end - start, segsize);
            (void) printf("\t\tsegment [%016llx, %016llx)"
                " size %5s\n", (u_longlong_t)start,
                (u_longlong_t)end, segsize);
            if (error)
                break;
            start = end;
        }
    }

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

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

/*ARGSUSED*/
static void
dump_dir(objset_t *os)
{
    dmu_objset_stats_t dds;
    uint64_t object, object_count;
    uint64_t refdbytes, usedobjs, scratch;
    char numbuf[8];
    char blkbuf[BP_SPRINTF_LEN];
    char osname[MAXNAMELEN];
    char *type = "UNKNOWN";
    int verbosity = dump_opt['d'];
    int print_header = 1;
    int i, error;

    dmu_objset_fast_stat(os, &dds);

    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 = os->os->os_rootbp->blk_fill;
        refdbytes =
            os->os->os_spa->spa_dsl_pool->dp_mos_dir->dd_used_bytes;
    } else {
        dmu_objset_space(os, &refdbytes, &scratch, &usedobjs, &scratch);
    }

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

    nicenum(refdbytes, numbuf);

    if (verbosity >= 4) {
        (void) strcpy(blkbuf, ", rootbp ");
        sprintf_blkptr(blkbuf + strlen(blkbuf),
            BP_SPRINTF_LEN - strlen(blkbuf), os->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\n",
        osname, type, (u_longlong_t)dmu_objset_id(os),
        (u_longlong_t)dds.dds_creation_txg,
        numbuf, (u_longlong_t)usedobjs, blkbuf);

    dump_intent_log(dmu_objset_zil(os));

    if (dmu_objset_ds(os) != NULL)
        dump_bplist(dmu_objset_pool(os)->dp_meta_objset,
            dmu_objset_ds(os)->ds_phys->ds_deadlist_obj, "Deadlist");

    if (verbosity < 2)
        return;

    if (zopt_objects != 0) {
        for (i = 0; i < zopt_objects; i++)
            dump_object(os, zopt_object[i], verbosity,
                &print_header);
        (void) printf("\n");
        return;
    }

    dump_object(os, 0, verbosity, &print_header);
    object_count = 1;

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

    ASSERT3U(object_count, ==, usedobjs);

    (void) printf("\n");

    if (error != ESRCH)
        fatal("dmu_object_next() = %d", error);
}

static void
dump_uberblock(uberblock_t *ub)
{
    time_t timestamp = ub->ub_timestamp;

    (void) printf("Uberblock\n\n");
    (void) printf("\tmagic = %016llx\n", (u_longlong_t)ub->ub_magic);
    (void) printf("\tversion = %llu\n", (u_longlong_t)ub->ub_version);
    (void) printf("\ttxg = %llu\n", (u_longlong_t)ub->ub_txg);
    (void) printf("\tguid_sum = %llu\n", (u_longlong_t)ub->ub_guid_sum);
    (void) printf("\ttimestamp = %llu UTC = %s",
        (u_longlong_t)ub->ub_timestamp, asctime(localtime(&timestamp)));
    if (dump_opt['u'] >= 3) {
        char blkbuf[BP_SPRINTF_LEN];
        sprintf_blkptr(blkbuf, BP_SPRINTF_LEN, &ub->ub_rootbp);
        (void) printf("\trootbp = %s\n", blkbuf);
    }
    (void) printf("\n");
}

static void
dump_config(const char *pool)
{
    spa_t *spa = NULL;

    mutex_enter(&spa_namespace_lock);
    while ((spa = spa_next(spa)) != NULL) {
        if (pool == NULL)
            (void) printf("%s\n", spa_name(spa));
        if (pool == NULL || strcmp(pool, spa_name(spa)) == 0)
            dump_nvlist(spa->spa_config, 4);
    }
    mutex_exit(&spa_namespace_lock);
}

static void
dump_label(const char *dev)
{
    int fd;
    vdev_label_t label;
    char *buf = label.vl_vdev_phys.vp_nvlist;
    size_t buflen = sizeof (label.vl_vdev_phys.vp_nvlist);
    struct stat64 statbuf;
    uint64_t psize;
    int l;

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

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

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

    for (l = 0; l < VDEV_LABELS; l++) {

        nvlist_t *config = NULL;

        (void) printf("--------------------------------------------\n");
        (void) printf("LABEL %d\n", l);
        (void) printf("--------------------------------------------\n");

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

        if (nvlist_unpack(buf, buflen, &config, 0) != 0) {
            (void) printf("failed to unpack label %d\n", l);
            continue;
        }
        dump_nvlist(config, 4);
        nvlist_free(config);
    }
}

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

    error = dmu_objset_open(dsname, DMU_OST_ANY,
        DS_MODE_STANDARD | DS_MODE_READONLY, &os);
    if (error) {
        (void) printf("Could not open %s\n", dsname);
        return (0);
    }
    dump_dir(os);
    dmu_objset_close(os);
    return (0);
}

static void
zdb_space_map_load(spa_t *spa)
{
    vdev_t *rvd = spa->spa_root_vdev;
    vdev_t *vd;
    int c, m, error;

    for (c = 0; c < rvd->vdev_children; c++) {
        vd = rvd->vdev_child[c];
        for (m = 0; m < vd->vdev_ms_count; m++) {
            metaslab_t *msp = vd->vdev_ms[m];
            mutex_enter(&msp->ms_lock);
            error = space_map_load(&msp->ms_allocmap[0], NULL,
                SM_ALLOC, &msp->ms_smo, spa->spa_meta_objset);
            mutex_exit(&msp->ms_lock);
            if (error)
                fatal("%s bad space map #%d, error %d",
                    spa->spa_name, c, error);
        }
    }
}

static int
zdb_space_map_claim(spa_t *spa, blkptr_t *bp, zbookmark_t *zb)
{
    dva_t *dva = bp->blk_dva;
    vdev_t *vd;
    metaslab_t *msp;
    space_map_t *allocmap, *freemap;
    int error;
    int d;
    blkptr_t blk = *bp;

    for (d = 0; d < BP_GET_NDVAS(bp); d++) {
        uint64_t vdev = DVA_GET_VDEV(&dva[d]);
        uint64_t offset = DVA_GET_OFFSET(&dva[d]);
        uint64_t size = DVA_GET_ASIZE(&dva[d]);

        if ((vd = vdev_lookup_top(spa, vdev)) == NULL)
            return (ENXIO);

        if ((offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count)
            return (ENXIO);

        msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
        allocmap = &msp->ms_allocmap[0];
        freemap = &msp->ms_freemap[0];

        /* Prepare our copy of the bp in case we need to read GBHs */
        if (DVA_GET_GANG(&dva[d])) {
            size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
            DVA_SET_ASIZE(&blk.blk_dva[d], size);
            DVA_SET_GANG(&blk.blk_dva[d], 0);
        }

        mutex_enter(&msp->ms_lock);
        if (space_map_contains(freemap, offset, size)) {
            mutex_exit(&msp->ms_lock);
            return (EAGAIN);    /* allocated more than once */
        }

        if (!space_map_contains(allocmap, offset, size)) {
            mutex_exit(&msp->ms_lock);
            return (ESTALE);    /* not allocated at all */
        }

        space_map_remove(allocmap, offset, size);
        space_map_add(freemap, offset, size);

        mutex_exit(&msp->ms_lock);
    }

    if (BP_IS_GANG(bp)) {
        zio_gbh_phys_t gbh;
        int g;

        /* LINTED - compile time assert */
        ASSERT(sizeof (zio_gbh_phys_t) == SPA_GANGBLOCKSIZE);

        BP_SET_CHECKSUM(&blk, ZIO_CHECKSUM_GANG_HEADER);
        BP_SET_PSIZE(&blk, SPA_GANGBLOCKSIZE);
        BP_SET_LSIZE(&blk, SPA_GANGBLOCKSIZE);
        BP_SET_COMPRESS(&blk, ZIO_COMPRESS_OFF);
        error = zio_wait(zio_read(NULL, spa, &blk, &gbh,
            SPA_GANGBLOCKSIZE, NULL, NULL, ZIO_PRIORITY_SYNC_READ,
            ZIO_FLAG_CANFAIL | ZIO_FLAG_CONFIG_HELD, zb));
        if (error)
            return (error);
        if (BP_SHOULD_BYTESWAP(&blk))
            byteswap_uint64_array(&gbh, SPA_GANGBLOCKSIZE);
        for (g = 0; g < SPA_GBH_NBLKPTRS; g++) {
            if (BP_IS_HOLE(&gbh.zg_blkptr[g]))
                break;
            error = zdb_space_map_claim(spa, &gbh.zg_blkptr[g], zb);
            if (error)
                return (error);
        }
    }

    return (0);
}

static void
zdb_leak(space_map_t *sm, uint64_t start, uint64_t size)
{
    metaslab_t *msp;

    /* LINTED */
    msp = (metaslab_t *)((char *)sm - offsetof(metaslab_t, ms_allocmap[0]));

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

static void
zdb_space_map_unload(spa_t *spa)
{
    vdev_t *rvd = spa->spa_root_vdev;
    vdev_t *vd;
    int c, m;

    for (c = 0; c < rvd->vdev_children; c++) {
        vd = rvd->vdev_child[c];
        for (m = 0; m < vd->vdev_ms_count; m++) {
            metaslab_t *msp = vd->vdev_ms[m];
            mutex_enter(&msp->ms_lock);
            space_map_vacate(&msp->ms_allocmap[0], zdb_leak,
                &msp->ms_allocmap[0]);
            space_map_unload(&msp->ms_allocmap[0]);
            space_map_vacate(&msp->ms_freemap[0], NULL, NULL);
            mutex_exit(&msp->ms_lock);
        }
    }
}

static void
zdb_refresh_ubsync(spa_t *spa)
{
    uberblock_t ub = { 0 };
    vdev_t *rvd = spa->spa_root_vdev;
    zio_t *zio;

    /*
     * Reload the uberblock.
     */
    zio = zio_root(spa, NULL, NULL,
        ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
    vdev_uberblock_load(zio, rvd, &ub);
    (void) zio_wait(zio);

    if (ub.ub_txg != 0)
        spa->spa_ubsync = ub;
}

/*
 * Verify that the sum of the sizes of all blocks in the pool adds up
 * to the SPA's sa_alloc total.
 */
typedef struct zdb_blkstats {
    uint64_t    zb_asize;
    uint64_t    zb_lsize;
    uint64_t    zb_psize;
    uint64_t    zb_count;
} zdb_blkstats_t;

#define DMU_OT_DEFERRED DMU_OT_NONE
#define DMU_OT_TOTAL    DMU_OT_NUMTYPES

#define ZB_TOTAL    ZB_MAXLEVEL

typedef struct zdb_cb {
    zdb_blkstats_t  zcb_type[ZB_TOTAL + 1][DMU_OT_TOTAL + 1];
    uint64_t    zcb_errors[256];
    traverse_blk_cache_t *zcb_cache;
    int     zcb_readfails;
    int     zcb_haderrors;
} zdb_cb_t;

static void
zdb_count_block(spa_t *spa, zdb_cb_t *zcb, blkptr_t *bp, int type)
{
    int i, error;

    for (i = 0; i < 4; i++) {
        int l = (i < 2) ? BP_GET_LEVEL(bp) : ZB_TOTAL;
        int t = (i & 1) ? type : DMU_OT_TOTAL;
        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++;
    }

    if (dump_opt['L'])
        return;

    error = zdb_space_map_claim(spa, bp, &zcb->zcb_cache->bc_bookmark);

    if (error == 0)
        return;

    if (error == EAGAIN)
        (void) fatal("double-allocation, bp=%p", bp);

    if (error == ESTALE)
        (void) fatal("reference to freed block, bp=%p", bp);

    (void) fatal("fatal error %d in bp %p", error, bp);
}

static int
zdb_blkptr_cb(traverse_blk_cache_t *bc, spa_t *spa, void *arg)
{
    zbookmark_t *zb = &bc->bc_bookmark;
    zdb_cb_t *zcb = arg;
    blkptr_t *bp = &bc->bc_blkptr;
    dmu_object_type_t type = BP_GET_TYPE(bp);
    char blkbuf[BP_SPRINTF_LEN];
    int error = 0;

    if (bc->bc_errno) {
        if (zcb->zcb_readfails++ < 10 && dump_opt['L']) {
            zdb_refresh_ubsync(spa);
            error = EAGAIN;
        } else {
            zcb->zcb_haderrors = 1;
            zcb->zcb_errors[bc->bc_errno]++;
            error = ERESTART;
        }

        if (dump_opt['b'] >= 3 || (dump_opt['b'] >= 2 && bc->bc_errno))
            sprintf_blkptr(blkbuf, BP_SPRINTF_LEN, bp);
        else
            blkbuf[0] = '\0';

        (void) printf("zdb_blkptr_cb: Got error %d reading "
            "<%llu, %llu, %lld, %llx> %s -- %s\n",
            bc->bc_errno,
            (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,
            error == EAGAIN ? "retrying" : "skipping");

        return (error);
    }

    zcb->zcb_readfails = 0;

    ASSERT(!BP_IS_HOLE(bp));

    if (dump_opt['b'] >= 4) {
        sprintf_blkptr(blkbuf, BP_SPRINTF_LEN, bp);
        (void) printf("objset %llu object %llu offset 0x%llx %s\n",
            (u_longlong_t)zb->zb_objset,
            (u_longlong_t)zb->zb_object,
            (u_longlong_t)blkid2offset(bc->bc_dnode,
            zb->zb_level, zb->zb_blkid), blkbuf);
    }

    zdb_count_block(spa, zcb, bp, type);

    return (0);
}

static int
dump_block_stats(spa_t *spa)
{
    traverse_handle_t *th;
    zdb_cb_t zcb = { 0 };
    traverse_blk_cache_t dummy_cache = { 0 };
    zdb_blkstats_t *zb, *tzb;
    uint64_t alloc, space, logalloc;
    vdev_t *rvd = spa->spa_root_vdev;
    int leaks = 0;
    int advance = zdb_advance;
    int c, e, flags;

    zcb.zcb_cache = &dummy_cache;

    if (dump_opt['c'])
        advance |= ADVANCE_DATA;

    advance |= ADVANCE_PRUNE | ADVANCE_ZIL;

    (void) printf("\nTraversing all blocks to %sverify"
        " nothing leaked ...\n",
        dump_opt['c'] ? "verify checksums and " : "");

    /*
     * Load all space maps.  As we traverse the pool, if we find a block
     * that's not in its space map, that indicates a double-allocation,
     * reference to a freed block, or an unclaimed block.  Otherwise we
     * remove the block from the space map.  If the space maps are not
     * empty when we're done, that indicates leaked blocks.
     */
    if (!dump_opt['L'])
        zdb_space_map_load(spa);

    /*
     * If there's a deferred-free bplist, process that first.
     */
    if (spa->spa_sync_bplist_obj != 0) {
        bplist_t *bpl = &spa->spa_sync_bplist;
        blkptr_t blk;
        uint64_t itor = 0;

        VERIFY(0 == bplist_open(bpl, spa->spa_meta_objset,
            spa->spa_sync_bplist_obj));

        while (bplist_iterate(bpl, &itor, &blk) == 0) {
            if (dump_opt['b'] >= 4) {
                char blkbuf[BP_SPRINTF_LEN];
                sprintf_blkptr(blkbuf, BP_SPRINTF_LEN, &blk);
                (void) printf("[%s] %s\n",
                    "deferred free", blkbuf);
            }
            zdb_count_block(spa, &zcb, &blk, DMU_OT_DEFERRED);
        }

        bplist_close(bpl);
    }

    /*
     * Now traverse the pool.  If we're reading all data to verify
     * checksums, do a scrubbing read so that we validate all copies.
     */
    flags = ZIO_FLAG_CANFAIL;
    if (advance & ADVANCE_DATA)
        flags |= ZIO_FLAG_SCRUB;
    th = traverse_init(spa, zdb_blkptr_cb, &zcb, advance, flags);
    th->th_noread = zdb_noread;

    traverse_add_pool(th, 0, spa_first_txg(spa) + TXG_CONCURRENT_STATES);

    while (traverse_more(th) == EAGAIN)
        continue;

    traverse_fini(th);

    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.
     */
    if (!dump_opt['L'])
        zdb_space_map_unload(spa);

    if (dump_opt['L'])
        (void) printf("\n\n *** Live pool traversal; "
            "block counts are only approximate ***\n\n");

    alloc = spa_get_alloc(spa);
    space = spa_get_space(spa);

    /*
     * Log blocks allocated from a separate log device don't count
     * as part of the normal pool space; factor them in here.
     */
    logalloc = 0;

    for (c = 0; c < rvd->vdev_children; c++)
        if (rvd->vdev_child[c]->vdev_islog)
            logalloc += rvd->vdev_child[c]->vdev_stat.vs_alloc;

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

    if (tzb->zb_asize == alloc + logalloc) {
        (void) printf("\n\tNo leaks (block sum matches space"
            " maps exactly)\n");
    } else {
        (void) printf("block traversal size %llu != alloc %llu "
            "(leaked %lld)\n",
            (u_longlong_t)tzb->zb_asize,
            (u_longlong_t)alloc + logalloc,
            (u_longlong_t)(alloc + logalloc - tzb->zb_asize));
        leaks = 1;
    }

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

    (void) printf("\n");
    (void) printf("\tbp count:      %10llu\n",
        (u_longlong_t)tzb->zb_count);
    (void) printf("\tbp logical:    %10llu\t avg: %6llu\n",
        (u_longlong_t)tzb->zb_lsize,
        (u_longlong_t)(tzb->zb_lsize / tzb->zb_count));
    (void) printf("\tbp physical:   %10llu\t avg:"
        " %6llu\tcompression: %6.2f\n",
        (u_longlong_t)tzb->zb_psize,
        (u_longlong_t)(tzb->zb_psize / tzb->zb_count),
        (double)tzb->zb_lsize / tzb->zb_psize);
    (void) printf("\tbp allocated:  %10llu\t avg:"
        " %6llu\tcompression: %6.2f\n",
        (u_longlong_t)tzb->zb_asize,
        (u_longlong_t)(tzb->zb_asize / tzb->zb_count),
        (double)tzb->zb_lsize / tzb->zb_asize);
    (void) printf("\tSPA allocated: %10llu\tused: %5.2f%%\n",
        (u_longlong_t)alloc, 100.0 * alloc / space);

    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 <= DMU_OT_NUMTYPES; t++) {
            char csize[6], lsize[6], psize[6], asize[6], avg[6];
            char *typename;

            typename = t == DMU_OT_DEFERRED ? "deferred free" :
                t == DMU_OT_TOTAL ? "Total" : dmu_ot[t].ot_name;

            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;

                nicenum(zb->zb_count, csize);
                nicenum(zb->zb_lsize, lsize);
                nicenum(zb->zb_psize, psize);
                nicenum(zb->zb_asize, asize);
                nicenum(zb->zb_asize / zb->zb_count, avg);

                (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);
            }
        }
    }

    (void) printf("\n");

    if (leaks)
        return (2);

    if (zcb.zcb_haderrors)
        return (3);

    return (0);
}

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

    if (dump_opt['u'])
        dump_uberblock(&spa->spa_uberblock);

    if (dump_opt['d'] || dump_opt['i']) {
        dump_dir(dp->dp_meta_objset);
        if (dump_opt['d'] >= 3) {
            dump_bplist(dp->dp_meta_objset,
                spa->spa_sync_bplist_obj, "Deferred frees");
            dump_dtl(spa->spa_root_vdev, 0);
            dump_metaslabs(spa);
        }
        (void) dmu_objset_find(spa->spa_name, dump_one_dir, NULL,
            DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);
    }

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

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

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

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

int flagbits[256];

static void
zdb_print_blkptr(blkptr_t *bp, int flags)
{
    dva_t *dva = bp->blk_dva;
    int d;

    if (flags & ZDB_FLAG_BSWAP)
        byteswap_uint64_array((void *)bp, sizeof (blkptr_t));
    /*
     * Super-ick warning:  This code is also duplicated in
     * cmd/mdb/common/modules/zfs/zfs.c .  Yeah, I hate code
     * replication, too.
     */
    for (d = 0; d < BP_GET_NDVAS(bp); d++) {
        (void) printf("\tDVA[%d]: vdev_id %lld / %llx\n", d,
            (longlong_t)DVA_GET_VDEV(&dva[d]),
            (longlong_t)DVA_GET_OFFSET(&dva[d]));
        (void) printf("\tDVA[%d]:       GANG: %-5s  GRID:  %04llx\t"
            "ASIZE: %llx\n", d,
            DVA_GET_GANG(&dva[d]) ? "TRUE" : "FALSE",
            (longlong_t)DVA_GET_GRID(&dva[d]),
            (longlong_t)DVA_GET_ASIZE(&dva[d]));
        (void) printf("\tDVA[%d]: :%llu:%llx:%llx:%s%s%s%s\n", d,
            (u_longlong_t)DVA_GET_VDEV(&dva[d]),
            (longlong_t)DVA_GET_OFFSET(&dva[d]),
            (longlong_t)BP_GET_PSIZE(bp),
            BP_SHOULD_BYTESWAP(bp) ? "e" : "",
            !DVA_GET_GANG(&dva[d]) && BP_GET_LEVEL(bp) != 0 ?
            "d" : "",
            DVA_GET_GANG(&dva[d]) ? "g" : "",
            BP_GET_COMPRESS(bp) != 0 ? "d" : "");
    }
    (void) printf("\tLSIZE:  %-16llx\t\tPSIZE: %llx\n",
        (longlong_t)BP_GET_LSIZE(bp), (longlong_t)BP_GET_PSIZE(bp));
    (void) printf("\tENDIAN: %6s\t\t\t\t\tTYPE:  %s\n",
        BP_GET_BYTEORDER(bp) ? "LITTLE" : "BIG",
        dmu_ot[BP_GET_TYPE(bp)].ot_name);
    (void) printf("\tBIRTH:  %-16llx   LEVEL: %-2llu\tFILL:  %llx\n",
        (u_longlong_t)bp->blk_birth, (u_longlong_t)BP_GET_LEVEL(bp),
        (u_longlong_t)bp->blk_fill);
    (void) printf("\tCKFUNC: %-16s\t\tCOMP:  %s\n",
        zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name,
        zio_compress_table[BP_GET_COMPRESS(bp)].ci_name);
    (void) printf("\tCKSUM:  %llx:%llx:%llx:%llx\n",
        (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
zdb_dump_indirect(blkptr_t *bp, int nbps, int flags)
{
    int i;

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

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

static void
zdb_dump_block_raw(void *buf, uint64_t size, int flags)
{
    if (flags & ZDB_FLAG_BSWAP)
        byteswap_uint64_array(buf, size);
    (void) write(2, buf, size);
}

static void
zdb_dump_block(char *label, void *buf, uint64_t size, int flags)
{
    uint64_t *d = (uint64_t *)buf;
    int nwords = size / sizeof (uint64_t);
    int do_bswap = !!(flags & ZDB_FLAG_BSWAP);
    int i, j;
    char *hdr, *c;


    if (do_bswap)
        hdr = " 7 6 5 4 3 2 1 0   f e d c b a 9 8";
    else
        hdr = " 0 1 2 3 4 5 6 7   8 9 a b c d e f";

    (void) printf("\n%s\n%6s   %s  0123456789abcdef\n", label, "", hdr);

    for (i = 0; i < nwords; i += 2) {
        (void) printf("%06llx:  %016llx  %016llx  ",
            (u_longlong_t)(i * sizeof (uint64_t)),
            (u_longlong_t)(do_bswap ? BSWAP_64(d[i]) : d[i]),
            (u_longlong_t)(do_bswap ? BSWAP_64(d[i + 1]) : d[i + 1]));

        c = (char *)&d[i];
        for (j = 0; j < 2 * sizeof (uint64_t); j++)
            (void) printf("%c", isprint(c[j]) ? c[j] : '.');
        (void) printf("\n");
    }
}

/*
 * There are two acceptable formats:
 *  leaf_name     - For example: c1t0d0 or /tmp/ztest.0a
 *  child[.child]*    - For example: 0.1.1
 *
 * The second form can be used to specify arbitrary vdevs anywhere
 * in the heirarchy.  For example, in a pool with a mirror of
 * RAID-Zs, you can specify either RAID-Z vdev with 0.0 or 0.1 .
 */
static vdev_t *
zdb_vdev_lookup(vdev_t *vdev, char *path)
{
    char *s, *p, *q;
    int i;

    if (vdev == NULL)
        return (NULL);

    /* First, assume the x.x.x.x format */
    i = (int)strtoul(path, &s, 10);
    if (s == path || (s && *s != '.' && *s != '\0'))
        goto name;
    if (i < 0 || i >= vdev->vdev_children)
        return (NULL);

    vdev = vdev->vdev_child[i];
    if (*s == '\0')
        return (vdev);
    return (zdb_vdev_lookup(vdev, s+1));

name:
    for (i = 0; i < vdev->vdev_children; i++) {
        vdev_t *vc = vdev->vdev_child[i];

        if (vc->vdev_path == NULL) {
            vc = zdb_vdev_lookup(vc, path);
            if (vc == NULL)
                continue;
            else
                return (vc);
        }

        p = strrchr(vc->vdev_path, '/');
        p = p ? p + 1 : vc->vdev_path;
        q = &vc->vdev_path[strlen(vc->vdev_path) - 2];

        if (strcmp(vc->vdev_path, path) == 0)
            return (vc);
        if (strcmp(p, path) == 0)
            return (vc);
        if (strcmp(q, "s0") == 0 && strncmp(p, path, q - p) == 0)
            return (vc);
    }

    return (NULL);
}

/*
 * Read a block from a pool and print it out.  The syntax of the
 * block descriptor is:
 *
 *  pool:vdev_specifier:offset:size[:flags]
 *
 *  pool           - The name of the pool you wish to read from
 *  vdev_specifier - Which vdev (see comment for zdb_vdev_lookup)
 *  offset         - offset, in hex, in bytes
 *  size           - Amount of data to read, in hex, in bytes
 *  flags          - A string of characters specifying options
 *       b: Decode a blkptr at given offset within block
 *      *c: Calculate and display checksums
 *      *d: Decompress data before dumping
 *       e: Byteswap data before dumping
 *      *g: Display data as a gang block header
 *      *i: Display as an indirect block
 *       p: Do I/O to physical offset
 *       r: Dump raw data to stdout
 *
 *              * = not yet implemented
 */
static void
zdb_read_block(char *thing, spa_t **spap)
{
    spa_t *spa = *spap;
    int flags = 0;
    uint64_t offset = 0, size = 0, blkptr_offset = 0;
    zio_t *zio;
    vdev_t *vd;
    void *buf;
    char *s, *p, *dup, *spa_name, *vdev, *flagstr;
    int i, error, zio_flags;

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

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

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

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

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

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

    if (spa == NULL || spa->spa_name == NULL ||
        strcmp(spa->spa_name, spa_name)) {
        if (spa && spa->spa_name)
            spa_close(spa, (void *)zdb_read_block);
        error = spa_open(spa_name, spap, (void *)zdb_read_block);
        if (error)
            fatal("Failed to open pool '%s': %s",
                spa_name, strerror(error));
        spa = *spap;
    }

    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) printf("Found vdev: %s\n", vd->vdev_path);
        else
            (void) printf("Found vdev type: %s\n",
                vd->vdev_ops->vdev_op_type);
    }

    buf = umem_alloc(size, UMEM_NOFAIL);

    zio_flags = ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE |
        ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_NOBOOKMARK;

    if (flags & ZDB_FLAG_PHYS)
        zio_flags |= ZIO_FLAG_PHYSICAL;

    zio = zio_root(spa, NULL, NULL, 0);
    /* XXX todo - cons up a BP so RAID-Z will be happy */
    zio_nowait(zio_vdev_child_io(zio, NULL, vd, offset, buf, size,
        ZIO_TYPE_READ, ZIO_PRIORITY_SYNC_READ, zio_flags, NULL, NULL));
    error = zio_wait(zio);

    if (error) {
        (void) printf("Read of %s failed, error: %d\n", thing, error);
        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, size, flags);
    else if (flags & ZDB_FLAG_INDIRECT)
        zdb_dump_indirect((blkptr_t *)buf, size / sizeof (blkptr_t),
            flags);
    else if (flags & ZDB_FLAG_GBH)
        zdb_dump_gbh(buf, flags);
    else
        zdb_dump_block(thing, buf, size, flags);

out:
    umem_free(buf, size);
    free(dup);
}

static boolean_t
nvlist_string_match(nvlist_t *config, char *name, char *tgt)
{
    char *s;

    verify(nvlist_lookup_string(config, name, &s) == 0);
    return (strcmp(s, tgt) == 0);
}

static boolean_t
nvlist_uint64_match(nvlist_t *config, char *name, uint64_t tgt)
{
    uint64_t val;

    verify(nvlist_lookup_uint64(config, name, &val) == 0);
    return (val == tgt);
}

static boolean_t
vdev_child_guid_match(nvlist_t *vdev, uint64_t guid)
{
    nvlist_t **child;
    uint_t c, children;

    verify(nvlist_lookup_nvlist_array(vdev, ZPOOL_CONFIG_CHILDREN,
        &child, &children) == 0);
    for (c = 0; c < children; ++c)
        if (nvlist_uint64_match(child[c], ZPOOL_CONFIG_GUID, guid))
            return (B_TRUE);
    return (B_FALSE);
}

static boolean_t
vdev_child_string_match(nvlist_t *vdev, char *tgt)
{
    nvlist_t **child;
    uint_t c, children;

    verify(nvlist_lookup_nvlist_array(vdev, ZPOOL_CONFIG_CHILDREN,
        &child, &children) == 0);
    for (c = 0; c < children; ++c) {
        if (nvlist_string_match(child[c], ZPOOL_CONFIG_PATH, tgt) ||
            nvlist_string_match(child[c], ZPOOL_CONFIG_DEVID, tgt))
            return (B_TRUE);
    }
    return (B_FALSE);
}

static boolean_t
vdev_guid_match(nvlist_t *config, uint64_t guid)
{
    nvlist_t *nvroot;

    verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
        &nvroot) == 0);

    return (nvlist_uint64_match(nvroot, ZPOOL_CONFIG_GUID, guid) ||
        vdev_child_guid_match(nvroot, guid));
}

static boolean_t
vdev_string_match(nvlist_t *config, char *tgt)
{
    nvlist_t *nvroot;

    verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
        &nvroot) == 0);

    return (vdev_child_string_match(nvroot, tgt));
}

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

    if (guid != 0) {
        return (
            nvlist_uint64_match(config, ZPOOL_CONFIG_POOL_GUID, guid) ||
            vdev_guid_match(config, guid));
    } else {
        return (
            nvlist_string_match(config, ZPOOL_CONFIG_POOL_NAME, tgt) ||
            vdev_string_match(config, tgt));
    }
}

static int
find_exported_zpool(char *pool_id, nvlist_t **configp, char *vdev_dir)
{
    nvlist_t *pools;
    int error = ENOENT;
    nvlist_t *match = NULL;

    if (vdev_dir != NULL)
        pools = zpool_find_import(g_zfs, 1, &vdev_dir);
    else
        pools = zpool_find_import(g_zfs, 0, NULL);

    if (pools != NULL) {
        nvpair_t *elem = NULL;

        while ((elem = nvlist_next_nvpair(pools, elem)) != NULL) {
            verify(nvpair_value_nvlist(elem, configp) == 0);
            if (pool_match(*configp, pool_id)) {
                if (match != NULL) {
                    (void) fatal(
                        "More than one matching pool - "
                        "specify guid/devid/device path.");
                } else {
                    match = *configp;
                    error = 0;
                }
            }
        }
    }

    *configp = error ? NULL : match;

    return (error);
}

int
main(int argc, char **argv)
{
    int i, c;
    struct rlimit rl = { 1024, 1024 };
    spa_t *spa;
    objset_t *os = NULL;
    char *endstr;
    int dump_all = 1;
    int verbose = 0;
    int error;
    int flag, set;
    int exported = 0;
    char *vdev_dir = NULL;

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

    dprintf_setup(&argc, argv);

    while ((c = getopt(argc, argv, "udibcsvCLO:B:UlRep:")) != -1) {
        switch (c) {
        case 'u':
        case 'd':
        case 'i':
        case 'b':
        case 'c':
        case 's':
        case 'C':
        case 'l':
        case 'R':
            dump_opt[c]++;
            dump_all = 0;
            break;
        case 'L':
            dump_opt[c]++;
            break;
        case 'O':
            endstr = optarg;
            if (endstr[0] == '!') {
                endstr++;
                set = 0;
            } else {
                set = 1;
            }
            if (strcmp(endstr, "post") == 0) {
                flag = ADVANCE_PRE;
                set = !set;
            } else if (strcmp(endstr, "pre") == 0) {
                flag = ADVANCE_PRE;
            } else if (strcmp(endstr, "prune") == 0) {
                flag = ADVANCE_PRUNE;
            } else if (strcmp(endstr, "data") == 0) {
                flag = ADVANCE_DATA;
            } else if (strcmp(endstr, "holes") == 0) {
                flag = ADVANCE_HOLES;
            } else {
                usage();
            }
            if (set)
                zdb_advance |= flag;
            else
                zdb_advance &= ~flag;
            break;
        case 'B':
            endstr = optarg - 1;
            zdb_noread.zb_objset = strtoull(endstr + 1, &endstr, 0);
            zdb_noread.zb_object = strtoull(endstr + 1, &endstr, 0);
            zdb_noread.zb_level = strtol(endstr + 1, &endstr, 0);
            zdb_noread.zb_blkid = strtoull(endstr + 1, &endstr, 16);
            (void) printf("simulating bad block "
                "<%llu, %llu, %lld, %llx>\n",
                (u_longlong_t)zdb_noread.zb_objset,
                (u_longlong_t)zdb_noread.zb_object,
                (u_longlong_t)zdb_noread.zb_level,
                (u_longlong_t)zdb_noread.zb_blkid);
            break;
        case 'v':
            verbose++;
            break;
        case 'U':
            spa_config_dir = "/tmp";
            break;
        case 'e':
            exported = 1;
            break;
        case 'p':
            vdev_dir = optarg;
            break;
        default:
            usage();
            break;
        }
    }

    if (vdev_dir != NULL && exported == 0)
        (void) fatal("-p option requires use of -e\n");

    kernel_init(FREAD);
    g_zfs = libzfs_init();
    ASSERT(g_zfs != NULL);

    /*
     * Disable vdev caching.  If we don't do this, live pool traversal
     * won't make progress because it will never see disk updates.
     */
    zfs_vdev_cache_size = 0;

    for (c = 0; c < 256; c++) {
        if (dump_all && c != 'L' && c != 'l' && c != 'R')
            dump_opt[c] = 1;
        if (dump_opt[c])
            dump_opt[c] += verbose;
    }

    argc -= optind;
    argv += optind;

    if (argc < 1) {
        if (dump_opt['C']) {
            dump_config(NULL);
            return (0);
        }
        usage();
    }

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

    if (dump_opt['R']) {
        flagbits['b'] = ZDB_FLAG_PRINT_BLKPTR;
        flagbits['c'] = ZDB_FLAG_CHECKSUM;
        flagbits['d'] = ZDB_FLAG_DECOMPRESS;
        flagbits['e'] = ZDB_FLAG_BSWAP;
        flagbits['g'] = ZDB_FLAG_GBH;
        flagbits['i'] = ZDB_FLAG_INDIRECT;
        flagbits['p'] = ZDB_FLAG_PHYS;
        flagbits['r'] = ZDB_FLAG_RAW;

        spa = NULL;
        while (argv[0]) {
            zdb_read_block(argv[0], &spa);
            argv++;
            argc--;
        }
        if (spa)
            spa_close(spa, (void *)zdb_read_block);
        return (0);
    }

    if (dump_opt['C'])
        dump_config(argv[0]);

    if (exported == 0) {
        if (strchr(argv[0], '/') != NULL) {
            error = dmu_objset_open(argv[0], DMU_OST_ANY,
                DS_MODE_STANDARD | DS_MODE_READONLY, &os);
        } else {
            error = spa_open(argv[0], &spa, FTAG);
        }
    } else {
        /*
         * Check to see if the name refers to an exported zpool
         */
        nvlist_t *exported_conf = NULL;

        error = find_exported_zpool(argv[0], &exported_conf, vdev_dir);
        if (error == 0) {
            error = spa_import(argv[0], exported_conf, vdev_dir);
            if (error == 0)
                error = spa_open(argv[0], &spa, FTAG);
        }
    }

    if (error)
        fatal("can't open %s: %s", argv[0], strerror(error));

    argv++;
    if (--argc > 0) {
        zopt_objects = argc;
        zopt_object = calloc(zopt_objects, sizeof (uint64_t));
        for (i = 0; i < zopt_objects; i++) {
            errno = 0;
            zopt_object[i] = strtoull(argv[i], NULL, 0);
            if (zopt_object[i] == 0 && errno != 0)
                fatal("bad object number %s: %s",
                    argv[i], strerror(errno));
        }
    }

    if (os != NULL) {
        dump_dir(os);
        dmu_objset_close(os);
    } else {
        dump_zpool(spa);
        spa_close(spa, FTAG);
    }

    libzfs_fini(g_zfs);
    kernel_fini();

    return (0);
}