fs/zfs/bpobj.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, 2014 by Delphix. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 */

#include <sys/bpobj.h>
#include <sys/zfs_context.h>
#include <sys/refcount.h>
#include <sys/dsl_pool.h>
#include <sys/zfeature.h>
#include <sys/zap.h>

/*
 * Return an empty bpobj, preferably the empty dummy one (dp_empty_bpobj).
 */
uint64_t
bpobj_alloc_empty(objset_t *os, int blocksize, dmu_tx_t *tx)
{
    spa_t *spa = dmu_objset_spa(os);
    dsl_pool_t *dp = dmu_objset_pool(os);

    if (spa_feature_is_enabled(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
        if (!spa_feature_is_active(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
            ASSERT0(dp->dp_empty_bpobj);
            dp->dp_empty_bpobj =
                bpobj_alloc(os, SPA_OLD_MAXBLOCKSIZE, tx);
            VERIFY(zap_add(os,
                DMU_POOL_DIRECTORY_OBJECT,
                DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
                &dp->dp_empty_bpobj, tx) == 0);
        }
        spa_feature_incr(spa, SPA_FEATURE_EMPTY_BPOBJ, tx);
        ASSERT(dp->dp_empty_bpobj != 0);
        return (dp->dp_empty_bpobj);
    } else {
        return (bpobj_alloc(os, blocksize, tx));
    }
}

void
bpobj_decr_empty(objset_t *os, dmu_tx_t *tx)
{
    dsl_pool_t *dp = dmu_objset_pool(os);

    spa_feature_decr(dmu_objset_spa(os), SPA_FEATURE_EMPTY_BPOBJ, tx);
    if (!spa_feature_is_active(dmu_objset_spa(os),
        SPA_FEATURE_EMPTY_BPOBJ)) {
        VERIFY3U(0, ==, zap_remove(dp->dp_meta_objset,
            DMU_POOL_DIRECTORY_OBJECT,
            DMU_POOL_EMPTY_BPOBJ, tx));
        VERIFY3U(0, ==, dmu_object_free(os, dp->dp_empty_bpobj, tx));
        dp->dp_empty_bpobj = 0;
    }
}

uint64_t
bpobj_alloc(objset_t *os, int blocksize, dmu_tx_t *tx)
{
    int size;

    if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_BPOBJ_ACCOUNT)
        size = BPOBJ_SIZE_V0;
    else if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_DEADLISTS)
        size = BPOBJ_SIZE_V1;
    else
        size = sizeof (bpobj_phys_t);

    return (dmu_object_alloc(os, DMU_OT_BPOBJ, blocksize,
        DMU_OT_BPOBJ_HDR, size, tx));
}

void
bpobj_free(objset_t *os, uint64_t obj, dmu_tx_t *tx)
{
    int64_t i;
    bpobj_t bpo;
    dmu_object_info_t doi;
    int epb;
    dmu_buf_t *dbuf = NULL;

    ASSERT(obj != dmu_objset_pool(os)->dp_empty_bpobj);
    VERIFY3U(0, ==, bpobj_open(&bpo, os, obj));

    mutex_enter(&bpo.bpo_lock);

    if (!bpo.bpo_havesubobj || bpo.bpo_phys->bpo_subobjs == 0)
        goto out;

    VERIFY3U(0, ==, dmu_object_info(os, bpo.bpo_phys->bpo_subobjs, &doi));
    epb = doi.doi_data_block_size / sizeof (uint64_t);

    for (i = bpo.bpo_phys->bpo_num_subobjs - 1; i >= 0; i--) {
        uint64_t *objarray;
        uint64_t offset, blkoff;

        offset = i * sizeof (uint64_t);
        blkoff = P2PHASE(i, epb);

        if (dbuf == NULL || dbuf->db_offset > offset) {
            if (dbuf)
                dmu_buf_rele(dbuf, FTAG);
            VERIFY3U(0, ==, dmu_buf_hold(os,
                bpo.bpo_phys->bpo_subobjs, offset, FTAG, &dbuf, 0));
        }

        ASSERT3U(offset, >=, dbuf->db_offset);
        ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);

        objarray = dbuf->db_data;
        bpobj_free(os, objarray[blkoff], tx);
    }
    if (dbuf) {
        dmu_buf_rele(dbuf, FTAG);
        dbuf = NULL;
    }
    VERIFY3U(0, ==, dmu_object_free(os, bpo.bpo_phys->bpo_subobjs, tx));

out:
    mutex_exit(&bpo.bpo_lock);
    bpobj_close(&bpo);

    VERIFY3U(0, ==, dmu_object_free(os, obj, tx));
}

int
bpobj_open(bpobj_t *bpo, objset_t *os, uint64_t object)
{
    dmu_object_info_t doi;
    int err;

    err = dmu_object_info(os, object, &doi);
    if (err)
        return (err);

    bzero(bpo, sizeof (*bpo));
    mutex_init(&bpo->bpo_lock, NULL, MUTEX_DEFAULT, NULL);

    ASSERT(bpo->bpo_dbuf == NULL);
    ASSERT(bpo->bpo_phys == NULL);
    ASSERT(object != 0);
    ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ);
    ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_BPOBJ_HDR);

    err = dmu_bonus_hold(os, object, bpo, &bpo->bpo_dbuf);
    if (err)
        return (err);

    bpo->bpo_os = os;
    bpo->bpo_object = object;
    bpo->bpo_epb = doi.doi_data_block_size >> SPA_BLKPTRSHIFT;
    bpo->bpo_havecomp = (doi.doi_bonus_size > BPOBJ_SIZE_V0);
    bpo->bpo_havesubobj = (doi.doi_bonus_size > BPOBJ_SIZE_V1);
    bpo->bpo_phys = bpo->bpo_dbuf->db_data;
    return (0);
}

void
bpobj_close(bpobj_t *bpo)
{
    /* Lame workaround for closing a bpobj that was never opened. */
    if (bpo->bpo_object == 0)
        return;

    dmu_buf_rele(bpo->bpo_dbuf, bpo);
    if (bpo->bpo_cached_dbuf != NULL)
        dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
    bpo->bpo_dbuf = NULL;
    bpo->bpo_phys = NULL;
    bpo->bpo_cached_dbuf = NULL;
    bpo->bpo_object = 0;

    mutex_destroy(&bpo->bpo_lock);
}

static boolean_t
bpobj_hasentries(bpobj_t *bpo)
{
    return (bpo->bpo_phys->bpo_num_blkptrs != 0 ||
        (bpo->bpo_havesubobj && bpo->bpo_phys->bpo_num_subobjs != 0));
}

static int
bpobj_iterate_impl(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx,
    boolean_t free)
{
    dmu_object_info_t doi;
    int epb;
    int64_t i;
    int err = 0;
    dmu_buf_t *dbuf = NULL;

    mutex_enter(&bpo->bpo_lock);

    if (free)
        dmu_buf_will_dirty(bpo->bpo_dbuf, tx);

    for (i = bpo->bpo_phys->bpo_num_blkptrs - 1; i >= 0; i--) {
        blkptr_t *bparray;
        blkptr_t *bp;
        uint64_t offset, blkoff;

        offset = i * sizeof (blkptr_t);
        blkoff = P2PHASE(i, bpo->bpo_epb);

        if (dbuf == NULL || dbuf->db_offset > offset) {
            if (dbuf)
                dmu_buf_rele(dbuf, FTAG);
            err = dmu_buf_hold(bpo->bpo_os, bpo->bpo_object, offset,
                FTAG, &dbuf, 0);
            if (err)
                break;
        }

        ASSERT3U(offset, >=, dbuf->db_offset);
        ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);

        bparray = dbuf->db_data;
        bp = &bparray[blkoff];
        err = func(arg, bp, tx);
        if (err)
            break;
        if (free) {
            bpo->bpo_phys->bpo_bytes -=
                bp_get_dsize_sync(dmu_objset_spa(bpo->bpo_os), bp);
            ASSERT3S(bpo->bpo_phys->bpo_bytes, >=, 0);
            if (bpo->bpo_havecomp) {
                bpo->bpo_phys->bpo_comp -= BP_GET_PSIZE(bp);
                bpo->bpo_phys->bpo_uncomp -= BP_GET_UCSIZE(bp);
            }
            bpo->bpo_phys->bpo_num_blkptrs--;
            ASSERT3S(bpo->bpo_phys->bpo_num_blkptrs, >=, 0);
        }
    }
    if (dbuf) {
        dmu_buf_rele(dbuf, FTAG);
        dbuf = NULL;
    }
    if (free) {
        VERIFY3U(0, ==, dmu_free_range(bpo->bpo_os, bpo->bpo_object,
            (i + 1) * sizeof (blkptr_t), -1ULL, tx));
    }
    if (err || !bpo->bpo_havesubobj || bpo->bpo_phys->bpo_subobjs == 0)
        goto out;

    ASSERT(bpo->bpo_havecomp);
    err = dmu_object_info(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, &doi);
    if (err) {
        mutex_exit(&bpo->bpo_lock);
        return (err);
    }
    ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ_SUBOBJ);
    epb = doi.doi_data_block_size / sizeof (uint64_t);

    for (i = bpo->bpo_phys->bpo_num_subobjs - 1; i >= 0; i--) {
        uint64_t *objarray;
        uint64_t offset, blkoff;
        bpobj_t sublist;
        uint64_t used_before, comp_before, uncomp_before;
        uint64_t used_after, comp_after, uncomp_after;

        offset = i * sizeof (uint64_t);
        blkoff = P2PHASE(i, epb);

        if (dbuf == NULL || dbuf->db_offset > offset) {
            if (dbuf)
                dmu_buf_rele(dbuf, FTAG);
            err = dmu_buf_hold(bpo->bpo_os,
                bpo->bpo_phys->bpo_subobjs, offset, FTAG, &dbuf, 0);
            if (err)
                break;
        }

        ASSERT3U(offset, >=, dbuf->db_offset);
        ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);

        objarray = dbuf->db_data;
        err = bpobj_open(&sublist, bpo->bpo_os, objarray[blkoff]);
        if (err)
            break;
        if (free) {
            err = bpobj_space(&sublist,
                &used_before, &comp_before, &uncomp_before);
            if (err != 0) {
                bpobj_close(&sublist);
                break;
            }
        }
        err = bpobj_iterate_impl(&sublist, func, arg, tx, free);
        if (free) {
            VERIFY3U(0, ==, bpobj_space(&sublist,
                &used_after, &comp_after, &uncomp_after));
            bpo->bpo_phys->bpo_bytes -= used_before - used_after;
            ASSERT3S(bpo->bpo_phys->bpo_bytes, >=, 0);
            bpo->bpo_phys->bpo_comp -= comp_before - comp_after;
            bpo->bpo_phys->bpo_uncomp -=
                uncomp_before - uncomp_after;
        }

        bpobj_close(&sublist);
        if (err)
            break;
        if (free) {
            err = dmu_object_free(bpo->bpo_os,
                objarray[blkoff], tx);
            if (err)
                break;
            bpo->bpo_phys->bpo_num_subobjs--;
            ASSERT3S(bpo->bpo_phys->bpo_num_subobjs, >=, 0);
        }
    }
    if (dbuf) {
        dmu_buf_rele(dbuf, FTAG);
        dbuf = NULL;
    }
    if (free) {
        VERIFY3U(0, ==, dmu_free_range(bpo->bpo_os,
            bpo->bpo_phys->bpo_subobjs,
            (i + 1) * sizeof (uint64_t), -1ULL, tx));
    }

out:
    /* If there are no entries, there should be no bytes. */
    if (!bpobj_hasentries(bpo)) {
        ASSERT0(bpo->bpo_phys->bpo_bytes);
        ASSERT0(bpo->bpo_phys->bpo_comp);
        ASSERT0(bpo->bpo_phys->bpo_uncomp);
    }

    mutex_exit(&bpo->bpo_lock);
    return (err);
}

/*
 * Iterate and remove the entries.  If func returns nonzero, iteration
 * will stop and that entry will not be removed.
 */
int
bpobj_iterate(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx)
{
    return (bpobj_iterate_impl(bpo, func, arg, tx, B_TRUE));
}

/*
 * Iterate the entries.  If func returns nonzero, iteration will stop.
 */
int
bpobj_iterate_nofree(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx)
{
    return (bpobj_iterate_impl(bpo, func, arg, tx, B_FALSE));
}

void
bpobj_enqueue_subobj(bpobj_t *bpo, uint64_t subobj, dmu_tx_t *tx)
{
    bpobj_t subbpo;
    uint64_t used, comp, uncomp, subsubobjs;

    ASSERT(bpo->bpo_havesubobj);
    ASSERT(bpo->bpo_havecomp);
    ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);

    if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj) {
        bpobj_decr_empty(bpo->bpo_os, tx);
        return;
    }

    VERIFY3U(0, ==, bpobj_open(&subbpo, bpo->bpo_os, subobj));
    VERIFY3U(0, ==, bpobj_space(&subbpo, &used, &comp, &uncomp));

    if (!bpobj_hasentries(&subbpo)) {
        /* No point in having an empty subobj. */
        bpobj_close(&subbpo);
        bpobj_free(bpo->bpo_os, subobj, tx);
        return;
    }

    dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
    if (bpo->bpo_phys->bpo_subobjs == 0) {
        bpo->bpo_phys->bpo_subobjs = dmu_object_alloc(bpo->bpo_os,
            DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
            DMU_OT_NONE, 0, tx);
    }

    dmu_object_info_t doi;
    ASSERT0(dmu_object_info(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, &doi));
    ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ_SUBOBJ);

    mutex_enter(&bpo->bpo_lock);
    dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
        bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
        sizeof (subobj), &subobj, tx);
    bpo->bpo_phys->bpo_num_subobjs++;

    /*
     * If subobj has only one block of subobjs, then move subobj's
     * subobjs to bpo's subobj list directly.  This reduces
     * recursion in bpobj_iterate due to nested subobjs.
     */
    subsubobjs = subbpo.bpo_phys->bpo_subobjs;
    if (subsubobjs != 0) {
        dmu_object_info_t doi;

        VERIFY3U(0, ==, dmu_object_info(bpo->bpo_os, subsubobjs, &doi));
        if (doi.doi_max_offset == doi.doi_data_block_size) {
            dmu_buf_t *subdb;
            uint64_t numsubsub = subbpo.bpo_phys->bpo_num_subobjs;

            VERIFY3U(0, ==, dmu_buf_hold(bpo->bpo_os, subsubobjs,
                0, FTAG, &subdb, 0));
            /*
             * Make sure that we are not asking dmu_write()
             * to write more data than we have in our buffer.
             */
            VERIFY3U(subdb->db_size, >=,
                numsubsub * sizeof (subobj));
            dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
                bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
                numsubsub * sizeof (subobj), subdb->db_data, tx);
            dmu_buf_rele(subdb, FTAG);
            bpo->bpo_phys->bpo_num_subobjs += numsubsub;

            dmu_buf_will_dirty(subbpo.bpo_dbuf, tx);
            subbpo.bpo_phys->bpo_subobjs = 0;
            VERIFY3U(0, ==, dmu_object_free(bpo->bpo_os,
                subsubobjs, tx));
        }
    }
    bpo->bpo_phys->bpo_bytes += used;
    bpo->bpo_phys->bpo_comp += comp;
    bpo->bpo_phys->bpo_uncomp += uncomp;
    mutex_exit(&bpo->bpo_lock);

    bpobj_close(&subbpo);
}

void
bpobj_enqueue(bpobj_t *bpo, const blkptr_t *bp, dmu_tx_t *tx)
{
    blkptr_t stored_bp = *bp;
    uint64_t offset;
    int blkoff;
    blkptr_t *bparray;

    ASSERT(!BP_IS_HOLE(bp));
    ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);

    if (BP_IS_EMBEDDED(bp)) {
        /*
         * The bpobj will compress better without the payload.
         *
         * Note that we store EMBEDDED bp's because they have an
         * uncompressed size, which must be accounted for.  An
         * alternative would be to add their size to bpo_uncomp
         * without storing the bp, but that would create additional
         * complications: bpo_uncomp would be inconsistent with the
         * set of BP's stored, and bpobj_iterate() wouldn't visit
         * all the space accounted for in the bpobj.
         */
        bzero(&stored_bp, sizeof (stored_bp));
        stored_bp.blk_prop = bp->blk_prop;
        stored_bp.blk_birth = bp->blk_birth;
    } else if (!BP_GET_DEDUP(bp)) {
        /* The bpobj will compress better without the checksum */
        bzero(&stored_bp.blk_cksum, sizeof (stored_bp.blk_cksum));
    }

    /* We never need the fill count. */
    stored_bp.blk_fill = 0;

    mutex_enter(&bpo->bpo_lock);

    offset = bpo->bpo_phys->bpo_num_blkptrs * sizeof (stored_bp);
    blkoff = P2PHASE(bpo->bpo_phys->bpo_num_blkptrs, bpo->bpo_epb);

    if (bpo->bpo_cached_dbuf == NULL ||
        offset < bpo->bpo_cached_dbuf->db_offset ||
        offset >= bpo->bpo_cached_dbuf->db_offset +
        bpo->bpo_cached_dbuf->db_size) {
        if (bpo->bpo_cached_dbuf)
            dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
        VERIFY3U(0, ==, dmu_buf_hold(bpo->bpo_os, bpo->bpo_object,
            offset, bpo, &bpo->bpo_cached_dbuf, 0));
    }

    dmu_buf_will_dirty(bpo->bpo_cached_dbuf, tx);
    bparray = bpo->bpo_cached_dbuf->db_data;
    bparray[blkoff] = stored_bp;

    dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
    bpo->bpo_phys->bpo_num_blkptrs++;
    bpo->bpo_phys->bpo_bytes +=
        bp_get_dsize_sync(dmu_objset_spa(bpo->bpo_os), bp);
    if (bpo->bpo_havecomp) {
        bpo->bpo_phys->bpo_comp += BP_GET_PSIZE(bp);
        bpo->bpo_phys->bpo_uncomp += BP_GET_UCSIZE(bp);
    }
    mutex_exit(&bpo->bpo_lock);
}

struct space_range_arg {
    spa_t *spa;
    uint64_t mintxg;
    uint64_t maxtxg;
    uint64_t used;
    uint64_t comp;
    uint64_t uncomp;
};

/* ARGSUSED */
static int
space_range_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
{
    struct space_range_arg *sra = arg;

    if (bp->blk_birth > sra->mintxg && bp->blk_birth <= sra->maxtxg) {
        if (dsl_pool_sync_context(spa_get_dsl(sra->spa)))
            sra->used += bp_get_dsize_sync(sra->spa, bp);
        else
            sra->used += bp_get_dsize(sra->spa, bp);
        sra->comp += BP_GET_PSIZE(bp);
        sra->uncomp += BP_GET_UCSIZE(bp);
    }
    return (0);
}

int
bpobj_space(bpobj_t *bpo, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
{
    mutex_enter(&bpo->bpo_lock);

    *usedp = bpo->bpo_phys->bpo_bytes;
    if (bpo->bpo_havecomp) {
        *compp = bpo->bpo_phys->bpo_comp;
        *uncompp = bpo->bpo_phys->bpo_uncomp;
        mutex_exit(&bpo->bpo_lock);
        return (0);
    } else {
        mutex_exit(&bpo->bpo_lock);
        return (bpobj_space_range(bpo, 0, UINT64_MAX,
            usedp, compp, uncompp));
    }
}

/*
 * Return the amount of space in the bpobj which is:
 * mintxg < blk_birth <= maxtxg
 */
int
bpobj_space_range(bpobj_t *bpo, uint64_t mintxg, uint64_t maxtxg,
    uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
{
    struct space_range_arg sra = { 0 };
    int err;

    /*
     * As an optimization, if they want the whole txg range, just
     * get bpo_bytes rather than iterating over the bps.
     */
    if (mintxg < TXG_INITIAL && maxtxg == UINT64_MAX && bpo->bpo_havecomp)
        return (bpobj_space(bpo, usedp, compp, uncompp));

    sra.spa = dmu_objset_spa(bpo->bpo_os);
    sra.mintxg = mintxg;
    sra.maxtxg = maxtxg;

    err = bpobj_iterate_nofree(bpo, space_range_cb, &sra, NULL);
    *usedp = sra.used;
    *compp = sra.comp;
    *uncompp = sra.uncomp;
    return (err);
}