/*
 * CDDL HEADER START
 *
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2013, 2014 by Delphix. All rights reserved.
 * Copyright 2017 Nexenta Systems, Inc.
 */

#include <sys/zfs_context.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_synctask.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/arc.h>
#include <sys/zap.h>
#include <sys/zfeature.h>
#include <sys/spa.h>
#include <sys/dsl_bookmark.h>
#include <zfs_namecheck.h>

static int
dsl_bookmark_hold_ds(dsl_pool_t *dp, const char *fullname,
    dsl_dataset_t **dsp, void *tag, char **shortnamep)
{
        char buf[ZFS_MAX_DATASET_NAME_LEN];
        char *hashp;

        if (strlen(fullname) >= ZFS_MAX_DATASET_NAME_LEN)
                return (SET_ERROR(ENAMETOOLONG));
        hashp = strchr(fullname, '#');
        if (hashp == NULL)
                return (SET_ERROR(EINVAL));

        *shortnamep = hashp + 1;
        if (zfs_component_namecheck(*shortnamep, NULL, NULL))
                return (SET_ERROR(EINVAL));
        (void) strlcpy(buf, fullname, hashp - fullname + 1);
        return (dsl_dataset_hold(dp, buf, tag, dsp));
}

/*
 * Returns ESRCH if bookmark is not found.
 */
static int
dsl_dataset_bmark_lookup(dsl_dataset_t *ds, const char *shortname,
    zfs_bookmark_phys_t *bmark_phys)
{
        objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
        uint64_t bmark_zapobj = ds->ds_bookmarks;
        matchtype_t mt = 0;
        int err;

        if (bmark_zapobj == 0)
                return (SET_ERROR(ESRCH));

        if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
                mt = MT_NORMALIZE;

        /*
         * Zero out the bookmark in case the one stored on disk
         * is in an older, shorter format.
         */
        bzero(bmark_phys, sizeof (*bmark_phys));

        err = zap_lookup_norm(mos, bmark_zapobj, shortname, sizeof (uint64_t),
            sizeof (*bmark_phys) / sizeof (uint64_t), bmark_phys, mt,
            NULL, 0, NULL);

        return (err == ENOENT ? ESRCH : err);
}

/*
 * If later_ds is non-NULL, this will return EXDEV if the the specified bookmark
 * does not represents an earlier point in later_ds's timeline.
 *
 * Returns ENOENT if the dataset containing the bookmark does not exist.
 * Returns ESRCH if the dataset exists but the bookmark was not found in it.
 */
int
dsl_bookmark_lookup(dsl_pool_t *dp, const char *fullname,
    dsl_dataset_t *later_ds, zfs_bookmark_phys_t *bmp)
{
        char *shortname;
        dsl_dataset_t *ds;
        int error;

        error = dsl_bookmark_hold_ds(dp, fullname, &ds, FTAG, &shortname);
        if (error != 0)
                return (error);

        error = dsl_dataset_bmark_lookup(ds, shortname, bmp);
        if (error == 0 && later_ds != NULL) {
                if (!dsl_dataset_is_before(later_ds, ds, bmp->zbm_creation_txg))
                        error = SET_ERROR(EXDEV);
        }
        dsl_dataset_rele(ds, FTAG);
        return (error);
}

typedef struct dsl_bookmark_create_arg {
        nvlist_t *dbca_bmarks;
        nvlist_t *dbca_errors;
} dsl_bookmark_create_arg_t;

static int
dsl_bookmark_create_check_impl(dsl_dataset_t *snapds, const char *bookmark_name,
    dmu_tx_t *tx)
{
        dsl_pool_t *dp = dmu_tx_pool(tx);
        dsl_dataset_t *bmark_fs;
        char *shortname;
        int error;
        zfs_bookmark_phys_t bmark_phys;

        if (!snapds->ds_is_snapshot)
                return (SET_ERROR(EINVAL));

        error = dsl_bookmark_hold_ds(dp, bookmark_name,
            &bmark_fs, FTAG, &shortname);
        if (error != 0)
                return (error);

        if (!dsl_dataset_is_before(bmark_fs, snapds, 0)) {
                dsl_dataset_rele(bmark_fs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        error = dsl_dataset_bmark_lookup(bmark_fs, shortname,
            &bmark_phys);
        dsl_dataset_rele(bmark_fs, FTAG);
        if (error == 0)
                return (SET_ERROR(EEXIST));
        if (error == ESRCH)
                return (0);
        return (error);
}

static int
dsl_bookmark_create_check(void *arg, dmu_tx_t *tx)
{
        dsl_bookmark_create_arg_t *dbca = arg;
        dsl_pool_t *dp = dmu_tx_pool(tx);
        int rv = 0;

        if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_BOOKMARKS))
                return (SET_ERROR(ENOTSUP));

        for (nvpair_t *pair = nvlist_next_nvpair(dbca->dbca_bmarks, NULL);
            pair != NULL; pair = nvlist_next_nvpair(dbca->dbca_bmarks, pair)) {
                dsl_dataset_t *snapds;
                int error;

                /* note: validity of nvlist checked by ioctl layer */
                error = dsl_dataset_hold(dp, fnvpair_value_string(pair),
                    FTAG, &snapds);
                if (error == 0) {
                        error = dsl_bookmark_create_check_impl(snapds,
                            nvpair_name(pair), tx);
                        dsl_dataset_rele(snapds, FTAG);
                }
                if (error != 0) {
                        fnvlist_add_int32(dbca->dbca_errors,
                            nvpair_name(pair), error);
                        rv = error;
                }
        }

        return (rv);
}

static void
dsl_bookmark_create_sync(void *arg, dmu_tx_t *tx)
{
        dsl_bookmark_create_arg_t *dbca = arg;
        dsl_pool_t *dp = dmu_tx_pool(tx);
        objset_t *mos = dp->dp_meta_objset;

        ASSERT(spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_BOOKMARKS));

        for (nvpair_t *pair = nvlist_next_nvpair(dbca->dbca_bmarks, NULL);
            pair != NULL; pair = nvlist_next_nvpair(dbca->dbca_bmarks, pair)) {
                dsl_dataset_t *snapds, *bmark_fs;
                zfs_bookmark_phys_t bmark_phys = { 0 };
                char *shortname;
                uint32_t bmark_len = BOOKMARK_PHYS_SIZE_V1;

                VERIFY0(dsl_dataset_hold(dp, fnvpair_value_string(pair),
                    FTAG, &snapds));
                VERIFY0(dsl_bookmark_hold_ds(dp, nvpair_name(pair),
                    &bmark_fs, FTAG, &shortname));
                if (bmark_fs->ds_bookmarks == 0) {
                        bmark_fs->ds_bookmarks =
                            zap_create_norm(mos, U8_TEXTPREP_TOUPPER,
                            DMU_OTN_ZAP_METADATA, DMU_OT_NONE, 0, tx);
                        spa_feature_incr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);

                        dsl_dataset_zapify(bmark_fs, tx);
                        VERIFY0(zap_add(mos, bmark_fs->ds_object,
                            DS_FIELD_BOOKMARK_NAMES,
                            sizeof (bmark_fs->ds_bookmarks), 1,
                            &bmark_fs->ds_bookmarks, tx));
                }

                bmark_phys.zbm_guid = dsl_dataset_phys(snapds)->ds_guid;
                bmark_phys.zbm_creation_txg =
                    dsl_dataset_phys(snapds)->ds_creation_txg;
                bmark_phys.zbm_creation_time =
                    dsl_dataset_phys(snapds)->ds_creation_time;

                /*
                 * If the dataset is encrypted create a larger bookmark to
                 * accommodate the IVset guid. The IVset guid was added
                 * after the encryption feature to prevent a problem with
                 * raw sends. If we encounter an encrypted dataset without
                 * an IVset guid we fall back to a normal bookmark.
                 */
                if (snapds->ds_dir->dd_crypto_obj != 0 &&
                    spa_feature_is_enabled(dp->dp_spa,
                    SPA_FEATURE_BOOKMARK_V2)) {
                        int err = zap_lookup(mos, snapds->ds_object,
                            DS_FIELD_IVSET_GUID, sizeof (uint64_t), 1,
                            &bmark_phys.zbm_ivset_guid);
                        if (err == 0) {
                                bmark_len = BOOKMARK_PHYS_SIZE_V2;
                                spa_feature_incr(dp->dp_spa,
                                    SPA_FEATURE_BOOKMARK_V2, tx);
                        }
                }

                VERIFY0(zap_add(mos, bmark_fs->ds_bookmarks,
                    shortname, sizeof (uint64_t),
                    bmark_len / sizeof (uint64_t), &bmark_phys, tx));

                spa_history_log_internal_ds(bmark_fs, "bookmark", tx,
                    "name=%s creation_txg=%llu target_snap=%llu",
                    shortname,
                    (longlong_t)bmark_phys.zbm_creation_txg,
                    (longlong_t)snapds->ds_object);

                dsl_dataset_rele(bmark_fs, FTAG);
                dsl_dataset_rele(snapds, FTAG);
        }
}

/*
 * The bookmarks must all be in the same pool.
 */
int
dsl_bookmark_create(nvlist_t *bmarks, nvlist_t *errors)
{
        nvpair_t *pair;
        dsl_bookmark_create_arg_t dbca;

        pair = nvlist_next_nvpair(bmarks, NULL);
        if (pair == NULL)
                return (0);

        dbca.dbca_bmarks = bmarks;
        dbca.dbca_errors = errors;

        return (dsl_sync_task(nvpair_name(pair), dsl_bookmark_create_check,
            dsl_bookmark_create_sync, &dbca,
            fnvlist_num_pairs(bmarks), ZFS_SPACE_CHECK_NORMAL));
}

int
dsl_get_bookmarks_impl(dsl_dataset_t *ds, nvlist_t *props, nvlist_t *outnvl)
{
        int err = 0;
        zap_cursor_t zc;
        zap_attribute_t attr;
        dsl_pool_t *dp = ds->ds_dir->dd_pool;

        uint64_t bmark_zapobj = ds->ds_bookmarks;
        if (bmark_zapobj == 0)
                return (0);

        for (zap_cursor_init(&zc, dp->dp_meta_objset, bmark_zapobj);
            zap_cursor_retrieve(&zc, &attr) == 0;
            zap_cursor_advance(&zc)) {
                char *bmark_name = attr.za_name;
                zfs_bookmark_phys_t bmark_phys = { 0 };

                err = dsl_dataset_bmark_lookup(ds, bmark_name, &bmark_phys);
                ASSERT3U(err, !=, ENOENT);
                if (err != 0)
                        break;

                nvlist_t *out_props = fnvlist_alloc();
                if (nvlist_exists(props,
                    zfs_prop_to_name(ZFS_PROP_GUID))) {
                        dsl_prop_nvlist_add_uint64(out_props,
                            ZFS_PROP_GUID, bmark_phys.zbm_guid);
                }
                if (nvlist_exists(props,
                    zfs_prop_to_name(ZFS_PROP_CREATETXG))) {
                        dsl_prop_nvlist_add_uint64(out_props,
                            ZFS_PROP_CREATETXG, bmark_phys.zbm_creation_txg);
                }
                if (nvlist_exists(props,
                    zfs_prop_to_name(ZFS_PROP_CREATION))) {
                        dsl_prop_nvlist_add_uint64(out_props,
                            ZFS_PROP_CREATION, bmark_phys.zbm_creation_time);
                }
                if (nvlist_exists(props,
                    zfs_prop_to_name(ZFS_PROP_IVSET_GUID))) {
                        dsl_prop_nvlist_add_uint64(out_props,
                            ZFS_PROP_IVSET_GUID, bmark_phys.zbm_ivset_guid);
                }

                fnvlist_add_nvlist(outnvl, bmark_name, out_props);
                fnvlist_free(out_props);
        }
        zap_cursor_fini(&zc);
        return (err);
}

/*
 * Retrieve the bookmarks that exist in the specified dataset, and the
 * requested properties of each bookmark.
 *
 * The "props" nvlist specifies which properties are requested.
 * See lzc_get_bookmarks() for the list of valid properties.
 */
int
dsl_get_bookmarks(const char *dsname, nvlist_t *props, nvlist_t *outnvl)
{
        dsl_pool_t *dp;
        dsl_dataset_t *ds;
        int err;

        err = dsl_pool_hold(dsname, FTAG, &dp);
        if (err != 0)
                return (err);
        err = dsl_dataset_hold(dp, dsname, FTAG, &ds);
        if (err != 0) {
                dsl_pool_rele(dp, FTAG);
                return (err);
        }

        err = dsl_get_bookmarks_impl(ds, props, outnvl);

        dsl_dataset_rele(ds, FTAG);
        dsl_pool_rele(dp, FTAG);
        return (err);
}

typedef struct dsl_bookmark_destroy_arg {
        nvlist_t *dbda_bmarks;
        nvlist_t *dbda_success;
        nvlist_t *dbda_errors;
} dsl_bookmark_destroy_arg_t;

static int
dsl_dataset_bookmark_remove(dsl_dataset_t *ds, const char *name, dmu_tx_t *tx)
{
        int err;
        objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
        uint64_t bmark_zapobj = ds->ds_bookmarks;
        matchtype_t mt = 0;
        uint64_t int_size, num_ints;

        if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
                mt = MT_NORMALIZE;

        err = zap_length(mos, bmark_zapobj, name, &int_size, &num_ints);
        if (err != 0)
                return (err);

        ASSERT3U(int_size, ==, sizeof (uint64_t));

        if (num_ints * int_size > BOOKMARK_PHYS_SIZE_V1) {
                spa_feature_decr(dmu_objset_spa(mos),
                    SPA_FEATURE_BOOKMARK_V2, tx);
        }

        return (zap_remove_norm(mos, bmark_zapobj, name, mt, tx));
}

static int
dsl_bookmark_destroy_check(void *arg, dmu_tx_t *tx)
{
        dsl_bookmark_destroy_arg_t *dbda = arg;
        dsl_pool_t *dp = dmu_tx_pool(tx);
        int rv = 0;

        ASSERT(nvlist_empty(dbda->dbda_success));
        ASSERT(nvlist_empty(dbda->dbda_errors));

        if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_BOOKMARKS))
                return (0);

        for (nvpair_t *pair = nvlist_next_nvpair(dbda->dbda_bmarks, NULL);
            pair != NULL; pair = nvlist_next_nvpair(dbda->dbda_bmarks, pair)) {
                const char *fullname = nvpair_name(pair);
                dsl_dataset_t *ds;
                zfs_bookmark_phys_t bm;
                int error;
                char *shortname;

                error = dsl_bookmark_hold_ds(dp, fullname, &ds,
                    FTAG, &shortname);
                if (error == ENOENT) {
                        /* ignore it; the bookmark is "already destroyed" */
                        continue;
                }
                if (error == 0) {
                        error = dsl_dataset_bmark_lookup(ds, shortname, &bm);
                        dsl_dataset_rele(ds, FTAG);
                        if (error == ESRCH) {
                                /*
                                 * ignore it; the bookmark is
                                 * "already destroyed"
                                 */
                                continue;
                        }
                }
                if (error == 0) {
                        if (dmu_tx_is_syncing(tx)) {
                                fnvlist_add_boolean(dbda->dbda_success,
                                    fullname);
                        }
                } else {
                        fnvlist_add_int32(dbda->dbda_errors, fullname, error);
                        rv = error;
                }
        }
        return (rv);
}

static void
dsl_bookmark_destroy_sync(void *arg, dmu_tx_t *tx)
{
        dsl_bookmark_destroy_arg_t *dbda = arg;
        dsl_pool_t *dp = dmu_tx_pool(tx);
        objset_t *mos = dp->dp_meta_objset;

        for (nvpair_t *pair = nvlist_next_nvpair(dbda->dbda_success, NULL);
            pair != NULL; pair = nvlist_next_nvpair(dbda->dbda_success, pair)) {
                dsl_dataset_t *ds;
                char *shortname;
                uint64_t zap_cnt;

                VERIFY0(dsl_bookmark_hold_ds(dp, nvpair_name(pair),
                    &ds, FTAG, &shortname));
                VERIFY0(dsl_dataset_bookmark_remove(ds, shortname, tx));

                /*
                 * If all of this dataset's bookmarks have been destroyed,
                 * free the zap object and decrement the feature's use count.
                 */
                VERIFY0(zap_count(mos, ds->ds_bookmarks,
                    &zap_cnt));
                if (zap_cnt == 0) {
                        dmu_buf_will_dirty(ds->ds_dbuf, tx);
                        VERIFY0(zap_destroy(mos, ds->ds_bookmarks, tx));
                        ds->ds_bookmarks = 0;
                        spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);
                        VERIFY0(zap_remove(mos, ds->ds_object,
                            DS_FIELD_BOOKMARK_NAMES, tx));
                }

                spa_history_log_internal_ds(ds, "remove bookmark", tx,
                    "name=%s", shortname);

                dsl_dataset_rele(ds, FTAG);
        }
}

/*
 * The bookmarks must all be in the same pool.
 */
int
dsl_bookmark_destroy(nvlist_t *bmarks, nvlist_t *errors)
{
        int rv;
        dsl_bookmark_destroy_arg_t dbda;
        nvpair_t *pair = nvlist_next_nvpair(bmarks, NULL);
        if (pair == NULL)
                return (0);

        dbda.dbda_bmarks = bmarks;
        dbda.dbda_errors = errors;
        dbda.dbda_success = fnvlist_alloc();

        rv = dsl_sync_task(nvpair_name(pair), dsl_bookmark_destroy_check,
            dsl_bookmark_destroy_sync, &dbda, fnvlist_num_pairs(bmarks),
            ZFS_SPACE_CHECK_RESERVED);
        fnvlist_free(dbda.dbda_success);
        return (rv);
}