C++ dmu_tx_pool函数代码示例

static void
dsl_dataset_user_hold_sync(void *arg, dmu_tx_t *tx)
{
	dsl_dataset_user_hold_arg_t *dduha = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	nvlist_t *tmpholds;
	nvpair_t *pair;
	uint64_t now = gethrestime_sec();

	if (dduha->dduha_minor != 0)
		tmpholds = fnvlist_alloc();
	else
		tmpholds = NULL;
	for (pair = nvlist_next_nvpair(dduha->dduha_chkholds, NULL);
	    pair != NULL;
	    pair = nvlist_next_nvpair(dduha->dduha_chkholds, pair)) {
		dsl_dataset_t *ds;

		VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
		dsl_dataset_user_hold_sync_one_impl(tmpholds, ds,
		    fnvpair_value_string(pair), dduha->dduha_minor, now, tx);
		dsl_dataset_rele(ds, FTAG);
	}
	dsl_onexit_hold_cleanup(dp->dp_spa, tmpholds, dduha->dduha_minor);
}

static void
dsl_dataset_user_release_sync(void *arg, dmu_tx_t *tx)
{
	dsl_dataset_user_release_arg_t *ddura = arg;
	dsl_holdfunc_t *holdfunc = ddura->ddura_holdfunc;
	dsl_pool_t *dp = dmu_tx_pool(tx);

	ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));

	for (nvpair_t *pair = nvlist_next_nvpair(ddura->ddura_chkholds, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(ddura->ddura_chkholds,
	    pair)) {
		dsl_dataset_t *ds;
		const char *name = nvpair_name(pair);

		VERIFY0(holdfunc(dp, name, FTAG, &ds));

		dsl_dataset_user_release_sync_one(ds,
		    fnvpair_value_nvlist(pair), tx);
		if (nvlist_exists(ddura->ddura_todelete, name)) {
			ASSERT(ds->ds_userrefs == 0 &&
			    ds->ds_phys->ds_num_children == 1 &&
			    DS_IS_DEFER_DESTROY(ds));
			dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
		}
		dsl_dataset_rele(ds, FTAG);
	}
}

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);
}

void
vdev_indirect_births_add_entry(vdev_indirect_births_t *vib,
    uint64_t max_offset, uint64_t txg, dmu_tx_t *tx)
{
	vdev_indirect_birth_entry_phys_t vibe;
	uint64_t old_size;
	uint64_t new_size;
	vdev_indirect_birth_entry_phys_t *new_entries;

	ASSERT(dmu_tx_is_syncing(tx));
	ASSERT(dsl_pool_sync_context(dmu_tx_pool(tx)));
	ASSERT(vdev_indirect_births_verify(vib));

	dmu_buf_will_dirty(vib->vib_dbuf, tx);

	vibe.vibe_offset = max_offset;
	vibe.vibe_phys_birth_txg = txg;

	old_size = vdev_indirect_births_size_impl(vib);
	dmu_write(vib->vib_objset, vib->vib_object, old_size, sizeof (vibe),
	    &vibe, tx);
	vib->vib_phys->vib_count++;
	new_size = vdev_indirect_births_size_impl(vib);

	new_entries = kmem_alloc(new_size, KM_SLEEP);
	if (old_size > 0) {
		bcopy(vib->vib_entries, new_entries, old_size);
		kmem_free(vib->vib_entries, old_size);
	}
	new_entries[vib->vib_phys->vib_count - 1] = vibe;
	vib->vib_entries = new_entries;
}

int
dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
{
	dsl_destroy_snapshot_arg_t *ddsa = arg;
	const char *dsname = ddsa->ddsa_name;
	boolean_t defer = ddsa->ddsa_defer;

	dsl_pool_t *dp = dmu_tx_pool(tx);
	int error = 0;
	dsl_dataset_t *ds;

	error = dsl_dataset_hold(dp, dsname, FTAG, &ds);

	/*
	 * If the snapshot does not exist, silently ignore it, and
	 * dsl_destroy_snapshot_sync() will be a no-op
	 * (it's "already destroyed").
	 */
	if (error == ENOENT)
		return (0);

	if (error == 0) {
		error = dsl_destroy_snapshot_check_impl(ds, defer);
		dsl_dataset_rele(ds, FTAG);
	}

	return (error);
}

/*
 * If you add new checks here, you may need to add additional checks to the
 * "temporary" case in snapshot_check() in dmu_objset.c.
 */
int
dsl_dataset_user_hold_check_one(dsl_dataset_t *ds, const char *htag,
    boolean_t temphold, dmu_tx_t *tx)
{
	dsl_pool_t *dp = dmu_tx_pool(tx);
	objset_t *mos = dp->dp_meta_objset;
	int error = 0;

	ASSERT(dsl_pool_config_held(dp));

	if (strlen(htag) > MAXNAMELEN)
		return (SET_ERROR(E2BIG));
	/* Tempholds have a more restricted length */
	if (temphold && strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
		return (SET_ERROR(E2BIG));

	/* tags must be unique (if ds already exists) */
	if (ds != NULL && ds->ds_phys->ds_userrefs_obj != 0) {
		uint64_t value;

		error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj,
		    htag, 8, 1, &value);
		if (error == 0)
			error = SET_ERROR(EEXIST);
		else if (error == ENOENT)
			error = 0;
	}

	return (error);
}

/*
 * Open-context function to add one entry to the new mapping.  The new
 * entry will be remembered and written from syncing context.
 */
static void
spa_condense_indirect_commit_entry(spa_t *spa,
    vdev_indirect_mapping_entry_phys_t *vimep, uint32_t count)
{
	spa_condensing_indirect_t *sci = spa->spa_condensing_indirect;

	ASSERT3U(count, <, DVA_GET_ASIZE(&vimep->vimep_dst));

	dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
	dmu_tx_hold_space(tx, sizeof (*vimep) + sizeof (count));
	VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
	int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;

	/*
	 * If we are the first entry committed this txg, kick off the sync
	 * task to write to the MOS on our behalf.
	 */
	if (list_is_empty(&sci->sci_new_mapping_entries[txgoff])) {
		dsl_sync_task_nowait(dmu_tx_pool(tx),
		    spa_condense_indirect_commit_sync, sci,
		    0, ZFS_SPACE_CHECK_NONE, tx);
	}

	vdev_indirect_mapping_entry_t *vime =
	    kmem_alloc(sizeof (*vime), KM_SLEEP);
	vime->vime_mapping = *vimep;
	vime->vime_obsolete_count = count;
	list_insert_tail(&sci->sci_new_mapping_entries[txgoff], vime);

	dmu_tx_commit(tx);
}

/*ARGSUSED*/
static int
dmu_objset_create_check(void *arg, dmu_tx_t *tx)
{
	dmu_objset_create_arg_t *doca = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	dsl_dir_t *pdd;
	const char *tail;
	int error;

	if (strchr(doca->doca_name, '@') != NULL)
		return (SET_ERROR(EINVAL));

	error = dsl_dir_hold(dp, doca->doca_name, FTAG, &pdd, &tail);
	if (error != 0)
		return (error);
	if (tail == NULL) {
		dsl_dir_rele(pdd, FTAG);
		return (SET_ERROR(EEXIST));
	}
	error = dsl_fs_ss_limit_check(pdd, 1, ZFS_PROP_FILESYSTEM_LIMIT, NULL,
	    doca->doca_cred);
	dsl_dir_rele(pdd, FTAG);

	return (error);
}

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_deleg_check(void *arg, dmu_tx_t *tx)
{
    dsl_deleg_arg_t *dda = arg;
    dsl_dir_t *dd;
    int error;

    if (spa_version(dmu_tx_pool(tx)->dp_spa) <
            SPA_VERSION_DELEGATED_PERMS) {
        return (SET_ERROR(ENOTSUP));
    }

    error = dsl_dir_hold(dmu_tx_pool(tx), dda->dda_name, FTAG, &dd, NULL);
    if (error == 0)
        dsl_dir_rele(dd, FTAG);
    return (error);
}

/* ARGSUSED */
static void
dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx)
{
	dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;

	dsl_scan_done(scn, B_FALSE, tx);
	dsl_scan_sync_state(scn, tx);
}

/*
 * This sync task completes (finishes) a condense, deleting the old
 * mapping and replacing it with the new one.
 */
static void
spa_condense_indirect_complete_sync(void *arg, dmu_tx_t *tx)
{
	spa_condensing_indirect_t *sci = arg;
	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
	spa_condensing_indirect_phys_t *scip =
	    &spa->spa_condensing_indirect_phys;
	vdev_t *vd = vdev_lookup_top(spa, scip->scip_vdev);
	vdev_indirect_config_t *vic = &vd->vdev_indirect_config;
	objset_t *mos = spa->spa_meta_objset;
	vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping;
	uint64_t old_count = vdev_indirect_mapping_num_entries(old_mapping);
	uint64_t new_count =
	    vdev_indirect_mapping_num_entries(sci->sci_new_mapping);

	ASSERT(dmu_tx_is_syncing(tx));
	ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);
	ASSERT3P(sci, ==, spa->spa_condensing_indirect);
	for (int i = 0; i < TXG_SIZE; i++) {
		ASSERT(list_is_empty(&sci->sci_new_mapping_entries[i]));
	}
	ASSERT(vic->vic_mapping_object != 0);
	ASSERT3U(vd->vdev_id, ==, scip->scip_vdev);
	ASSERT(scip->scip_next_mapping_object != 0);
	ASSERT(scip->scip_prev_obsolete_sm_object != 0);

	/*
	 * Reset vdev_indirect_mapping to refer to the new object.
	 */
	rw_enter(&vd->vdev_indirect_rwlock, RW_WRITER);
	vdev_indirect_mapping_close(vd->vdev_indirect_mapping);
	vd->vdev_indirect_mapping = sci->sci_new_mapping;
	rw_exit(&vd->vdev_indirect_rwlock);

	sci->sci_new_mapping = NULL;
	vdev_indirect_mapping_free(mos, vic->vic_mapping_object, tx);
	vic->vic_mapping_object = scip->scip_next_mapping_object;
	scip->scip_next_mapping_object = 0;

	space_map_free_obj(mos, scip->scip_prev_obsolete_sm_object, tx);
	spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx);
	scip->scip_prev_obsolete_sm_object = 0;

	scip->scip_vdev = 0;

	VERIFY0(zap_remove(mos, DMU_POOL_DIRECTORY_OBJECT,
	    DMU_POOL_CONDENSING_INDIRECT, tx));
	spa_condensing_indirect_destroy(spa->spa_condensing_indirect);
	spa->spa_condensing_indirect = NULL;

	zfs_dbgmsg("finished condense of vdev %llu in txg %llu: "
	    "new mapping object %llu has %llu entries "
	    "(was %llu entries)",
	    vd->vdev_id, dmu_tx_get_txg(tx), vic->vic_mapping_object,
	    new_count, old_count);

	vdev_config_dirty(spa->spa_root_vdev);
}

/* ARGSUSED */
static int
dsl_scan_cancel_check(void *arg, dmu_tx_t *tx)
{
	dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;

	if (scn->scn_phys.scn_state != DSS_SCANNING)
		return (SET_ERROR(ENOENT));
	return (0);
}

/* ARGSUSED */
static int
dsl_scan_setup_check(void *arg, dmu_tx_t *tx)
{
	dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;

	if (scn->scn_phys.scn_state == DSS_SCANNING)
		return (SET_ERROR(EBUSY));

	return (0);
}

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;
	nvpair_t *pair;

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

	for (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;
		char *shortname;

		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;

		VERIFY0(zap_add(mos, bmark_fs->ds_bookmarks,
		    shortname, sizeof (uint64_t),
		    sizeof (zfs_bookmark_phys_t) / 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);
	}
}