C++ dsl_dataset_hold_obj函数代码示例

int
dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
{
	int err;
	dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
	dsl_dir_t *dd;
	dsl_dataset_t *ds;
	uint64_t obj;

	rw_enter(&dp->dp_config_rwlock, RW_WRITER);
	err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
	    &dp->dp_meta_objset);
	if (err)
		goto out;

	err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
	    DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,
	    &dp->dp_root_dir_obj);
	if (err)
		goto out;

	err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
	    NULL, dp, &dp->dp_root_dir);
	if (err)
		goto out;

	err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir);
	if (err)
		goto out;

	if (spa_version(spa) >= SPA_VERSION_ORIGIN) {
		err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd);
		if (err)
			goto out;
		err = dsl_dataset_hold_obj(dp, dd->dd_phys->dd_head_dataset_obj,
		    FTAG, &ds);
		if (err == 0) {
			err = dsl_dataset_hold_obj(dp,
			    ds->ds_phys->ds_prev_snap_obj, dp,
			    &dp->dp_origin_snap);
			dsl_dataset_rele(ds, FTAG);
		}
		dsl_dir_close(dd, dp);
		if (err)
			goto out;
	}

	if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
		err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME,
		    &dp->dp_free_dir);
		if (err)
			goto out;

		err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
		    DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj);
		if (err)
			goto out;
		VERIFY3U(0, ==, bpobj_open(&dp->dp_free_bpobj,
		    dp->dp_meta_objset, obj));
	}

static int
zcp_clones_iter(lua_State *state)
{
	int err;
	char clonename[ZFS_MAX_DATASET_NAME_LEN];
	uint64_t dsobj = lua_tonumber(state, lua_upvalueindex(1));
	uint64_t cursor = lua_tonumber(state, lua_upvalueindex(2));
	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
	dsl_dataset_t *ds, *clone;
	zap_attribute_t za;
	zap_cursor_t zc;

	err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
	if (err == ENOENT) {
		return (0);
	} else if (err != 0) {
		return (luaL_error(state,
		    "unexpected error %d from dsl_dataset_hold_obj(dsobj)",
		    err));
	}

	if (dsl_dataset_phys(ds)->ds_next_clones_obj == 0) {
		dsl_dataset_rele(ds, FTAG);
		return (0);
	}

	zap_cursor_init_serialized(&zc, dp->dp_meta_objset,
	    dsl_dataset_phys(ds)->ds_next_clones_obj, cursor);
	dsl_dataset_rele(ds, FTAG);

	err = zap_cursor_retrieve(&zc, &za);
	if (err != 0) {
		zap_cursor_fini(&zc);
		if (err != ENOENT) {
			return (luaL_error(state,
			    "unexpected error %d from zap_cursor_retrieve()",
			    err));
		}
		return (0);
	}
	zap_cursor_advance(&zc);
	cursor = zap_cursor_serialize(&zc);
	zap_cursor_fini(&zc);

	err = dsl_dataset_hold_obj(dp, za.za_first_integer, FTAG, &clone);
	if (err != 0) {
		return (luaL_error(state,
		    "unexpected error %d from "
		    "dsl_dataset_hold_obj(za_first_integer)", err));
	}

	dsl_dir_name(clone->ds_dir, clonename);
	dsl_dataset_rele(clone, FTAG);

	lua_pushnumber(state, cursor);
	lua_replace(state, lua_upvalueindex(2));

	(void) lua_pushstring(state, clonename);
	return (1);
}

void
dsl_dir_stats(dsl_dir_t *dd, nvlist_t *nv)
{
	mutex_enter(&dd->dd_lock);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, dd->dd_used_bytes);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_QUOTA, dd->dd_phys->dd_quota);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_RESERVATION,
	    dd->dd_phys->dd_reserved);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO,
	    dd->dd_phys->dd_compressed_bytes == 0 ? 100 :
	    (dd->dd_phys->dd_uncompressed_bytes * 100 /
	    dd->dd_phys->dd_compressed_bytes));
	mutex_exit(&dd->dd_lock);

	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
	if (dsl_dir_is_clone(dd)) {
		dsl_dataset_t *ds;
		char buf[MAXNAMELEN];

		VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
		    dd->dd_phys->dd_origin_obj, FTAG, &ds));
		dsl_dataset_name(ds, buf);
		dsl_dataset_rele(ds, FTAG);
		dsl_prop_nvlist_add_string(nv, ZFS_PROP_ORIGIN, buf);
	}
	rw_exit(&dd->dd_pool->dp_config_rwlock);
}

static void
dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
{
	objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
	zap_cursor_t zc;
	zap_attribute_t za;

	/*
	 * If it is the old version, dd_clones doesn't exist so we can't
	 * find the clones, but dsl_deadlist_remove_key() is a no-op so it
	 * doesn't matter.
	 */
	if (dsl_dir_phys(ds->ds_dir)->dd_clones == 0)
		return;

	for (zap_cursor_init(&zc, mos, dsl_dir_phys(ds->ds_dir)->dd_clones);
	    zap_cursor_retrieve(&zc, &za) == 0;
	    zap_cursor_advance(&zc)) {
		dsl_dataset_t *clone;

		VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
		    za.za_first_integer, FTAG, &clone));
		if (clone->ds_dir->dd_origin_txg > mintxg) {
			dsl_deadlist_remove_key(&clone->ds_deadlist,
			    mintxg, tx);
			dsl_dataset_remove_clones_key(clone, mintxg, tx);
		}
		dsl_dataset_rele(clone, FTAG);
	}
	zap_cursor_fini(&zc);
}

/*
 * Called at spa_load time to release a stale temporary user hold.
 * Also called by the onexit code.
 */
void
dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, const char *htag)
{
	dsl_dataset_user_release_tmp_arg_t ddurta;

#ifdef _KERNEL
	dsl_dataset_t *ds;
	int error;

	/* Make sure it is not mounted. */
	dsl_pool_config_enter(dp, FTAG);
	error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
	if (error == 0) {
		char name[MAXNAMELEN];
		dsl_dataset_name(ds, name);
		dsl_dataset_rele(ds, FTAG);
		dsl_pool_config_exit(dp, FTAG);
		zfs_unmount_snap(name);
	} else {
		dsl_pool_config_exit(dp, FTAG);
	}
#endif

	ddurta.ddurta_dsobj = dsobj;
	ddurta.ddurta_holds = fnvlist_alloc();
	fnvlist_add_boolean(ddurta.ddurta_holds, htag);

	(void) dsl_sync_task(spa_name(dp->dp_spa),
	    dsl_dataset_user_release_tmp_check,
	    dsl_dataset_user_release_tmp_sync, &ddurta, 1);
	fnvlist_free(ddurta.ddurta_holds);
}

static void
dmu_objset_create_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
{
	dsl_dir_t *dd = arg1;
	struct oscarg *oa = arg2;
	dsl_dataset_t *ds;
	blkptr_t *bp;
	uint64_t dsobj;

	ASSERT(dmu_tx_is_syncing(tx));

	dsobj = dsl_dataset_create_sync(dd, oa->lastname,
	    oa->clone_parent, oa->flags, cr, tx);

	VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, dsobj, FTAG, &ds));
	bp = dsl_dataset_get_blkptr(ds);
	if (BP_IS_HOLE(bp)) {
		objset_impl_t *osi;

		/* This is an empty dmu_objset; not a clone. */
		osi = dmu_objset_create_impl(dsl_dataset_get_spa(ds),
		    ds, bp, oa->type, tx);

		if (oa->userfunc)
			oa->userfunc(&osi->os, oa->userarg, cr, tx);
	}

	spa_history_internal_log(LOG_DS_CREATE, dd->dd_pool->dp_spa,
	    tx, cr, "dataset = %llu", dsobj);

	dsl_dataset_rele(ds, FTAG);
}

void
dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
{
#ifdef ZFS_DEBUG
	int err;
#endif
	int after_branch_point = FALSE;
	dsl_pool_t *dp = ds->ds_dir->dd_pool;
	objset_t *mos = dp->dp_meta_objset;
	dsl_dataset_t *ds_prev = NULL;
	uint64_t obj, old_unique, used = 0, comp = 0, uncomp = 0;
	dsl_dataset_t *ds_next, *ds_head, *hds;


	ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
	ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
	ASSERT(refcount_is_zero(&ds->ds_longholds));

	if (defer &&
	    (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)) {
		ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
		dmu_buf_will_dirty(ds->ds_dbuf, tx);
		ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
		spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
		return;
	}

	ASSERT3U(ds->ds_phys->ds_num_children, <=, 1);

	/* We need to log before removing it from the namespace. */
	spa_history_log_internal_ds(ds, "destroy", tx, "");

	dsl_scan_ds_destroyed(ds, tx);

	obj = ds->ds_object;

	if (ds->ds_phys->ds_prev_snap_obj != 0) {
		ASSERT3P(ds->ds_prev, ==, NULL);
		VERIFY0(dsl_dataset_hold_obj(dp,
		    ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
		after_branch_point =
		    (ds_prev->ds_phys->ds_next_snap_obj != obj);

		dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
		if (after_branch_point &&
		    ds_prev->ds_phys->ds_next_clones_obj != 0) {
			dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
			if (ds->ds_phys->ds_next_snap_obj != 0) {
				VERIFY0(zap_add_int(mos,
				    ds_prev->ds_phys->ds_next_clones_obj,
				    ds->ds_phys->ds_next_snap_obj, tx));
			}
		}
		if (!after_branch_point) {
			ds_prev->ds_phys->ds_next_snap_obj =
			    ds->ds_phys->ds_next_snap_obj;
		}
	}

static void
dsl_dataset_user_release_tmp_sync(void *arg, dmu_tx_t *tx)
{
	dsl_dataset_user_release_tmp_arg_t *ddurta = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	dsl_dataset_t *ds;

	VERIFY0(dsl_dataset_hold_obj(dp, ddurta->ddurta_dsobj, FTAG, &ds));
	dsl_dataset_user_release_sync_one(ds, ddurta->ddurta_holds, tx);
	if (ddurta->ddurta_deleteme) {
		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
zcp_children_iter(lua_State *state)
{
	int err;
	char childname[ZFS_MAX_DATASET_NAME_LEN];
	uint64_t dsobj = lua_tonumber(state, lua_upvalueindex(1));
	uint64_t cursor = lua_tonumber(state, lua_upvalueindex(2));
	zcp_run_info_t *ri = zcp_run_info(state);
	dsl_pool_t *dp = ri->zri_pool;
	dsl_dataset_t *ds;
	objset_t *os;
	char *p;

	err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
	if (err != 0) {
		return (luaL_error(state,
		    "unexpected error %d from dsl_dataset_hold_obj(dsobj)",
		    err));
	}

	dsl_dataset_name(ds, childname);
	VERIFY3U(sizeof (childname), >,
	    strlcat(childname, "/", sizeof (childname)));
	p = strchr(childname, '\0');

	VERIFY0(dmu_objset_from_ds(ds, &os));
	do {
		err = dmu_dir_list_next(os,
		    sizeof (childname) - (p - childname), p, NULL, &cursor);
	} while (err == 0 && dataset_name_hidden(childname));
	dsl_dataset_rele(ds, FTAG);

	if (err == ENOENT) {
		return (0);
	} else if (err != 0) {
		return (luaL_error(state,
		    "unexpected error %d from dmu_dir_list_next()",
		    err));
	}

	lua_pushnumber(state, cursor);
	lua_replace(state, lua_upvalueindex(2));

	(void) lua_pushstring(state, childname);
	return (1);
}

zcrypt_keystore_node_t *
zcrypt_keystore_find_node(spa_t *spa, uint64_t dsobj,
    boolean_t config_rwlock_held)
{
	zcrypt_keystore_node_t search;
	zcrypt_keystore_node_t *found = NULL;

	rw_enter(&spa->spa_keystore->sk_lock, RW_READER);
	if (avl_is_empty(&spa->spa_keystore->sk_dslkeys))
		goto out;

	search.skn_os = dsobj;
	found = avl_find(&spa->spa_keystore->sk_dslkeys, &search, NULL);
	if (found == NULL) {
		int error;
		dsl_pool_t *dp = spa_get_dsl(spa);
		dsl_dataset_t *ds;
		boolean_t need_lock;

		rw_exit(&spa->spa_keystore->sk_lock);
		need_lock = !dsl_pool_sync_context(dp) && !config_rwlock_held;
		if (need_lock)
			rw_enter(&dp->dp_config_rwlock, RW_READER);
		error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
		if (need_lock)
			rw_exit(&dp->dp_config_rwlock);
		rw_enter(&spa->spa_keystore->sk_lock, RW_READER);

		if (!error) {
			if (dsl_dataset_is_snapshot(ds)) {
				search.skn_os =
				    ds->ds_dir->dd_phys->dd_head_dataset_obj;
				found = avl_find(&spa->spa_keystore->sk_dslkeys,
				    &search, NULL);
			}
			dsl_dataset_rele(ds, FTAG);
		}
	}
out:
	rw_exit(&spa->spa_keystore->sk_lock);

	return (found);
}

static int
dsl_dataset_user_release_tmp_check(void *arg, dmu_tx_t *tx)
{
	dsl_dataset_user_release_tmp_arg_t *ddurta = arg;
	dsl_pool_t *dp = dmu_tx_pool(tx);
	dsl_dataset_t *ds;
	int error;

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

	error = dsl_dataset_hold_obj(dp, ddurta->ddurta_dsobj, FTAG, &ds);
	if (error)
		return (error);

	error = dsl_dataset_user_release_check_one(ds,
	    ddurta->ddurta_holds, &ddurta->ddurta_deleteme);
	dsl_dataset_rele(ds, FTAG);
	return (error);
}

void
dsl_dir_stats(dsl_dir_t *dd, nvlist_t *nv)
{
	mutex_enter(&dd->dd_lock);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
	    dd->dd_phys->dd_used_bytes);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_QUOTA, dd->dd_phys->dd_quota);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_RESERVATION,
	    dd->dd_phys->dd_reserved);
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO,
	    dd->dd_phys->dd_compressed_bytes == 0 ? 100 :
	    (dd->dd_phys->dd_uncompressed_bytes * 100 /
	    dd->dd_phys->dd_compressed_bytes));
	dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALUSED,
	    dd->dd_phys->dd_uncompressed_bytes);
	if (dd->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
		dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDSNAP,
		    dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]);
		dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDDS,
		    dd->dd_phys->dd_used_breakdown[DD_USED_HEAD]);
		dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDREFRESERV,
		    dd->dd_phys->dd_used_breakdown[DD_USED_REFRSRV]);
		dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDCHILD,
		    dd->dd_phys->dd_used_breakdown[DD_USED_CHILD] +
		    dd->dd_phys->dd_used_breakdown[DD_USED_CHILD_RSRV]);
	}
	mutex_exit(&dd->dd_lock);

	if (dsl_dir_is_clone(dd)) {
		dsl_dataset_t *ds;
		char buf[MAXNAMELEN];

		VERIFY0(dsl_dataset_hold_obj(dd->dd_pool,
		    dd->dd_phys->dd_origin_obj, FTAG, &ds));
		dsl_dataset_name(ds, buf);
		dsl_dataset_rele(ds, FTAG);
		dsl_prop_nvlist_add_string(nv, ZFS_PROP_ORIGIN, buf);
	}
}

void
dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
{
	int err;
	int after_branch_point = FALSE;
	dsl_pool_t *dp = ds->ds_dir->dd_pool;
	objset_t *mos = dp->dp_meta_objset;
	dsl_dataset_t *ds_prev = NULL;
	uint64_t obj;

	ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
	rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
	ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
	rrw_exit(&ds->ds_bp_rwlock, FTAG);
	ASSERT(refcount_is_zero(&ds->ds_longholds));

	if (defer &&
	    (ds->ds_userrefs > 0 ||
	    dsl_dataset_phys(ds)->ds_num_children > 1)) {
		ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
		dmu_buf_will_dirty(ds->ds_dbuf, tx);
		dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_DEFER_DESTROY;
		spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
		return;
	}

	ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);

	/* We need to log before removing it from the namespace. */
	spa_history_log_internal_ds(ds, "destroy", tx, "");

	dsl_scan_ds_destroyed(ds, tx);

	obj = ds->ds_object;

	boolean_t book_exists = dsl_bookmark_ds_destroyed(ds, tx);

	for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
		if (dsl_dataset_feature_is_active(ds, f))
			dsl_dataset_deactivate_feature(ds, f, tx);
	}
	if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
		ASSERT3P(ds->ds_prev, ==, NULL);
		VERIFY0(dsl_dataset_hold_obj(dp,
		    dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &ds_prev));
		after_branch_point =
		    (dsl_dataset_phys(ds_prev)->ds_next_snap_obj != obj);

		dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
		if (after_branch_point &&
		    dsl_dataset_phys(ds_prev)->ds_next_clones_obj != 0) {
			dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
			if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) {
				VERIFY0(zap_add_int(mos,
				    dsl_dataset_phys(ds_prev)->
				    ds_next_clones_obj,
				    dsl_dataset_phys(ds)->ds_next_snap_obj,
				    tx));
			}
		}
		if (!after_branch_point) {
			dsl_dataset_phys(ds_prev)->ds_next_snap_obj =
			    dsl_dataset_phys(ds)->ds_next_snap_obj;
		}
	}

			dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
			if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) {
				VERIFY0(zap_add_int(mos,
				    dsl_dataset_phys(ds_prev)->
				    ds_next_clones_obj,
				    dsl_dataset_phys(ds)->ds_next_snap_obj,
				    tx));
			}
		}
		if (!after_branch_point) {
			dsl_dataset_phys(ds_prev)->ds_next_snap_obj =
			    dsl_dataset_phys(ds)->ds_next_snap_obj;
		}
	}

	VERIFY0(dsl_dataset_hold_obj(dp,
	    dsl_dataset_phys(ds)->ds_next_snap_obj, FTAG, &ds_next));
	ASSERT3U(dsl_dataset_phys(ds_next)->ds_prev_snap_obj, ==, obj);

	old_unique = dsl_dataset_phys(ds_next)->ds_unique_bytes;

	dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
	dsl_dataset_phys(ds_next)->ds_prev_snap_obj =
	    dsl_dataset_phys(ds)->ds_prev_snap_obj;
	dsl_dataset_phys(ds_next)->ds_prev_snap_txg =
	    dsl_dataset_phys(ds)->ds_prev_snap_txg;
	ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, ==,
	    ds_prev ? dsl_dataset_phys(ds_prev)->ds_creation_txg : 0);

	if (ds_next->ds_deadlist.dl_oldfmt) {
		process_old_deadlist(ds, ds_prev, ds_next,
		    after_branch_point, tx);

/* Place a dataset hold on the snapshot identified by passed dsobj string */
static int
dsl_dataset_hold_obj_string(dsl_pool_t *dp, const char *dsobj, void *tag,
    dsl_dataset_t **dsp)
{
	return (dsl_dataset_hold_obj(dp, strtonum(dsobj, NULL), tag, dsp));
}