C++ dsl_dataset_hold函数代码示例

int
dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl)
{
	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);
	}

	if (dsl_dataset_phys(ds)->ds_userrefs_obj != 0) {
		zap_attribute_t *za;
		zap_cursor_t zc;

		za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
		for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
		    dsl_dataset_phys(ds)->ds_userrefs_obj);
		    zap_cursor_retrieve(&zc, za) == 0;
		    zap_cursor_advance(&zc)) {
			fnvlist_add_uint64(nvl, za->za_name,
			    za->za_first_integer);
		}
		zap_cursor_fini(&zc);
		kmem_free(za, sizeof (zap_attribute_t));
	}
	dsl_dataset_rele(ds, FTAG);
	dsl_pool_rele(dp, FTAG);
	return (0);
}

/* called from zpl */
int
dmu_objset_open(const char *name, dmu_objset_type_t type, int mode,
    objset_t **osp)
{
	objset_t *os;
	dsl_dataset_t *ds;
	int err;

	ASSERT(DS_MODE_TYPE(mode) == DS_MODE_USER ||
	    DS_MODE_TYPE(mode) == DS_MODE_OWNER);

	os = kmem_alloc(sizeof (objset_t), KM_SLEEP);
	if (DS_MODE_TYPE(mode) == DS_MODE_USER)
		err = dsl_dataset_hold(name, os, &ds);
	else
		err = dsl_dataset_own(name, mode, os, &ds);
	if (err) {
		kmem_free(os, sizeof (objset_t));
		return (err);
	}

	err = dmu_objset_open_ds_os(ds, os, type);
	if (err) {
		if (DS_MODE_TYPE(mode) == DS_MODE_USER)
			dsl_dataset_rele(ds, os);
		else
			dsl_dataset_disown(ds, os);
		kmem_free(os, sizeof (objset_t));
	} else {
		os->os_mode = mode;
		*osp = os;
	}
	return (err);
}

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;
	nvpair_t *pair;

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

	for (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
dmu_objset_clone_sync(void *arg, dmu_tx_t *tx)
{
	dmu_objset_clone_arg_t *doca = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	dsl_dir_t *pdd;
	const char *tail;
	dsl_dataset_t *origin, *ds;
	uint64_t obj;
	char namebuf[MAXNAMELEN];

	VERIFY0(dsl_dir_hold(dp, doca->doca_clone, FTAG, &pdd, &tail));
	VERIFY0(dsl_dataset_hold(dp, doca->doca_origin, FTAG, &origin));

	obj = dsl_dataset_create_sync(pdd, tail, origin, 0,
	    doca->doca_cred, tx);

	VERIFY0(dsl_dataset_hold_obj(pdd->dd_pool, obj, FTAG, &ds));
	dsl_dataset_name(origin, namebuf);
	spa_history_log_internal_ds(ds, "clone", tx,
	    "origin=%s (%llu)", namebuf, origin->ds_object);
	dsl_dataset_rele(ds, FTAG);
	dsl_dataset_rele(origin, FTAG);
	dsl_dir_rele(pdd, FTAG);
}

/* ARGSUSED */
int
dmu_objset_prefetch(char *name, void *arg)
{
	dsl_dataset_t *ds;

	if (dsl_dataset_hold(name, FTAG, &ds))
		return (0);

	if (!BP_IS_HOLE(&ds->ds_phys->ds_bp)) {
		mutex_enter(&ds->ds_opening_lock);
		if (!dsl_dataset_get_user_ptr(ds)) {
			uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
			zbookmark_t zb;

			zb.zb_objset = ds->ds_object;
			zb.zb_object = 0;
			zb.zb_level = -1;
			zb.zb_blkid = 0;

			(void) arc_read_nolock(NULL, dsl_dataset_get_spa(ds),
			    &ds->ds_phys->ds_bp, NULL, NULL,
			    ZIO_PRIORITY_ASYNC_READ,
			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
			    &aflags, &zb);
		}
		mutex_exit(&ds->ds_opening_lock);
	}

	dsl_dataset_rele(ds, FTAG);
	return (0);
}

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);
}

/*
 * Note: will longjmp (via lua_error()) on error.
 * Assumes that the dsname is argument #1 (for error reporting purposes).
 */
dsl_dataset_t *
zcp_dataset_hold(lua_State *state, dsl_pool_t *dp, const char *dsname,
    void *tag)
{
	dsl_dataset_t *ds;
	int error = dsl_dataset_hold(dp, dsname, tag, &ds);
	(void) zcp_dataset_hold_error(state, dp, dsname, error);
	return (ds);
}

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);
	}
}

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

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

	error = dsl_dir_hold(dp, doca->doca_clone, FTAG, &pdd, &tail);
	if (error != 0)
		return (error);
	if (tail == NULL) {
		dsl_dir_rele(pdd, FTAG);
		return (SET_ERROR(EEXIST));
	}
	/* You can't clone across pools. */
	if (pdd->dd_pool != dp) {
		dsl_dir_rele(pdd, FTAG);
		return (SET_ERROR(EXDEV));
	}
	error = dsl_fs_ss_limit_check(pdd, 1, ZFS_PROP_FILESYSTEM_LIMIT, NULL,
	    doca->doca_cred);
	if (error != 0) {
		dsl_dir_rele(pdd, FTAG);
		return (SET_ERROR(EDQUOT));
	}
	dsl_dir_rele(pdd, FTAG);

	error = dsl_dataset_hold(dp, doca->doca_origin, FTAG, &origin);
	if (error != 0)
		return (error);

	/* You can't clone across pools. */
	if (origin->ds_dir->dd_pool != dp) {
		dsl_dataset_rele(origin, FTAG);
		return (SET_ERROR(EXDEV));
	}

	/* You can only clone snapshots, not the head datasets. */
	if (!dsl_dataset_is_snapshot(origin)) {
		dsl_dataset_rele(origin, FTAG);
		return (SET_ERROR(EINVAL));
	}
	dsl_dataset_rele(origin, FTAG);

	return (0);
}

static int
dsl_dataset_user_hold_check(void *arg, dmu_tx_t *tx)
{
	dsl_dataset_user_hold_arg_t *dduha = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	nvpair_t *pair;

	if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS)
		return (SET_ERROR(ENOTSUP));

	if (!dmu_tx_is_syncing(tx))
		return (0);

	for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
		dsl_dataset_t *ds;
		int error = 0;
		char *htag, *name;

		/* must be a snapshot */
		name = nvpair_name(pair);
		if (strchr(name, '@') == NULL)
			error = SET_ERROR(EINVAL);

		if (error == 0)
			error = nvpair_value_string(pair, &htag);

		if (error == 0)
			error = dsl_dataset_hold(dp, name, FTAG, &ds);

		if (error == 0) {
			error = dsl_dataset_user_hold_check_one(ds, htag,
			    dduha->dduha_minor != 0, tx);
			dsl_dataset_rele(ds, FTAG);
		}

		if (error == 0) {
			fnvlist_add_string(dduha->dduha_chkholds, name, htag);
		} else {
			/*
			 * We register ENOENT errors so they can be correctly
			 * reported if needed, such as when all holds fail.
			 */
			fnvlist_add_int32(dduha->dduha_errlist, name, error);
			if (error != ENOENT)
				return (error);
		}
	}

	return (0);
}

int
dsl_deleg_access(const char *dsname, const char *perm, cred_t *cr)
{
	dsl_dataset_t *ds;
	int error;

	error = dsl_dataset_hold(dsname, FTAG, &ds);
	if (error)
		return (error);

	error = dsl_deleg_access_impl(ds, B_FALSE, perm, cr);
	dsl_dataset_rele(ds, FTAG);

	return (error);
}

/* called from zpl */
int
dmu_objset_hold(const char *name, void *tag, objset_t **osp)
{
	dsl_dataset_t *ds;
	int err;

	err = dsl_dataset_hold(name, tag, &ds);
	if (err)
		return (err);

	err = dmu_objset_from_ds(ds, osp);
	if (err)
		dsl_dataset_rele(ds, tag);

	return (err);
}

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);
	nvpair_t *pair;
	uint64_t now = gethrestime_sec();

	for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL); pair != NULL;
	    pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
		dsl_dataset_t *ds;
		VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
		dsl_dataset_user_hold_sync_one(ds, fnvpair_value_string(pair),
		    dduha->dduha_minor, now, tx);
		dsl_dataset_rele(ds, FTAG);
	}
}

static int
dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
{
	dmu_snapshots_destroy_arg_t *dsda = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	nvpair_t *pair;
	int error = 0;

	if (!dmu_tx_is_syncing(tx))
		return (0);

	for (pair = nvlist_next_nvpair(dsda->dsda_snaps, NULL);
	    pair != NULL; pair = nvlist_next_nvpair(dsda->dsda_snaps, pair)) {
		dsl_dataset_t *ds;

		error = dsl_dataset_hold(dp, nvpair_name(pair),
		    FTAG, &ds);

		/*
		 * If the snapshot does not exist, silently ignore it
		 * (it's "already destroyed").
		 */
		if (error == ENOENT)
			continue;

		if (error == 0) {
			error = dsl_destroy_snapshot_check_impl(ds,
			    dsda->dsda_defer);
			dsl_dataset_rele(ds, FTAG);
		}

		if (error == 0) {
			fnvlist_add_boolean(dsda->dsda_successful_snaps,
			    nvpair_name(pair));
		} else {
			fnvlist_add_int32(dsda->dsda_errlist,
			    nvpair_name(pair), error);
		}
	}

	pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL);
	if (pair != NULL)
		return (fnvpair_value_int32(pair));

	return (0);
}

int
dsl_prop_get(const char *dsname, const char *propname,
    int intsz, int numints, void *buf, char *setpoint)
{
	dsl_dataset_t *ds;
	int err;

	err = dsl_dataset_hold(dsname, FTAG, &ds);
	if (err)
		return (err);

	rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
	err = dsl_prop_get_ds(ds, propname, intsz, numints, buf, setpoint);
	rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);

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