Ejemplo n.º 1
0
/*
 * Alter table space options
 */
Oid
AlterTableSpaceOptions(AlterTableSpaceOptionsStmt *stmt)
{
	Relation	rel;
	ScanKeyData entry[1];
	HeapScanDesc scandesc;
	HeapTuple	tup;
	Oid			tablespaceoid;
	Datum		datum;
	Datum		newOptions;
	Datum		repl_val[Natts_pg_tablespace];
	bool		isnull;
	bool		repl_null[Natts_pg_tablespace];
	bool		repl_repl[Natts_pg_tablespace];
	HeapTuple	newtuple;

	/* Search pg_tablespace */
	rel = heap_open(TableSpaceRelationId, RowExclusiveLock);

	ScanKeyInit(&entry[0],
				Anum_pg_tablespace_spcname,
				BTEqualStrategyNumber, F_NAMEEQ,
				CStringGetDatum(stmt->tablespacename));
	scandesc = heap_beginscan_catalog(rel, 1, entry);
	tup = heap_getnext(scandesc, ForwardScanDirection);
	if (!HeapTupleIsValid(tup))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("tablespace \"%s\" does not exist",
						stmt->tablespacename)));

	tablespaceoid = HeapTupleGetOid(tup);

	/* Must be owner of the existing object */
	if (!pg_tablespace_ownercheck(HeapTupleGetOid(tup), GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TABLESPACE,
					   stmt->tablespacename);

	/* Generate new proposed spcoptions (text array) */
	datum = heap_getattr(tup, Anum_pg_tablespace_spcoptions,
						 RelationGetDescr(rel), &isnull);
	newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
									 stmt->options, NULL, NULL, false,
									 stmt->isReset);
	(void) tablespace_reloptions(newOptions, true);

	/* Build new tuple. */
	memset(repl_null, false, sizeof(repl_null));
	memset(repl_repl, false, sizeof(repl_repl));
	if (newOptions != (Datum) 0)
		repl_val[Anum_pg_tablespace_spcoptions - 1] = newOptions;
	else
		repl_null[Anum_pg_tablespace_spcoptions - 1] = true;
	repl_repl[Anum_pg_tablespace_spcoptions - 1] = true;
	newtuple = heap_modify_tuple(tup, RelationGetDescr(rel), repl_val,
								 repl_null, repl_repl);

	/* Update system catalog. */
	simple_heap_update(rel, &newtuple->t_self, newtuple);
	CatalogUpdateIndexes(rel, newtuple);

	InvokeObjectPostAlterHook(TableSpaceRelationId, HeapTupleGetOid(tup), 0);

	heap_freetuple(newtuple);

	/* Conclude heap scan. */
	heap_endscan(scandesc);
	heap_close(rel, NoLock);

	return tablespaceoid;
}
Ejemplo n.º 2
0
/*
 * get_tablespace
 *		Fetch TableSpaceCacheEntry structure for a specified table OID.
 *
 * Pointers returned by this function should not be stored, since a cache
 * flush will invalidate them.
 */
static TableSpaceCacheEntry *
get_tablespace(Oid spcid)
{
	TableSpaceCacheEntry *spc;
	HeapTuple	tp;
	TableSpaceOpts *opts;

	/*
	 * Since spcid is always from a pg_class tuple, InvalidOid implies the
	 * default.
	 */
	if (spcid == InvalidOid)
		spcid = MyDatabaseTableSpace;

	/* Find existing cache entry, if any. */
	if (!TableSpaceCacheHash)
		InitializeTableSpaceCache();
	spc = (TableSpaceCacheEntry *) hash_search(TableSpaceCacheHash,
											   (void *) &spcid,
											   HASH_FIND,
											   NULL);
	if (spc)
		return spc;

	/*
	 * Not found in TableSpace cache.  Check catcache.	If we don't find a
	 * valid HeapTuple, it must mean someone has managed to request tablespace
	 * details for a non-existent tablespace.  We'll just treat that case as
	 * if no options were specified.
	 */
	tp = SearchSysCache1(TABLESPACEOID, ObjectIdGetDatum(spcid));
	if (!HeapTupleIsValid(tp))
		opts = NULL;
	else
	{
		Datum		datum;
		bool		isNull;

		datum = SysCacheGetAttr(TABLESPACEOID,
								tp,
								Anum_pg_tablespace_spcoptions,
								&isNull);
		if (isNull)
			opts = NULL;
		else
		{
			bytea	   *bytea_opts = tablespace_reloptions(datum, false);

			opts = MemoryContextAlloc(CacheMemoryContext, VARSIZE(bytea_opts));
			memcpy(opts, bytea_opts, VARSIZE(bytea_opts));
		}
		ReleaseSysCache(tp);
	}

	/*
	 * Now create the cache entry.	It's important to do this only after
	 * reading the pg_tablespace entry, since doing so could cause a cache
	 * flush.
	 */
	spc = (TableSpaceCacheEntry *) hash_search(TableSpaceCacheHash,
											   (void *) &spcid,
											   HASH_ENTER,
											   NULL);
	spc->opts = opts;
	return spc;
}
Ejemplo n.º 3
0
/*
 * Create a table space
 *
 * Only superusers can create a tablespace. This seems a reasonable restriction
 * since we're determining the system layout and, anyway, we probably have
 * root if we're doing this kind of activity
 */
Oid
CreateTableSpace(CreateTableSpaceStmt *stmt)
{
#ifdef HAVE_SYMLINK
	Relation	rel;
	Datum		values[Natts_pg_tablespace];
	bool		nulls[Natts_pg_tablespace];
	HeapTuple	tuple;
	Oid			tablespaceoid;
	char	   *location;
	Oid			ownerId;
	Datum		newOptions;

	/* Must be super user */
	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 errmsg("permission denied to create tablespace \"%s\"",
						stmt->tablespacename),
				 errhint("Must be superuser to create a tablespace.")));

	/* However, the eventual owner of the tablespace need not be */
	if (stmt->owner)
		ownerId = get_rolespec_oid(stmt->owner, false);
	else
		ownerId = GetUserId();

	/* Unix-ify the offered path, and strip any trailing slashes */
	location = pstrdup(stmt->location);
	canonicalize_path(location);

	/* disallow quotes, else CREATE DATABASE would be at risk */
	if (strchr(location, '\''))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_NAME),
				 errmsg("tablespace location cannot contain single quotes")));

	/*
	 * Allowing relative paths seems risky
	 *
	 * this also helps us ensure that location is not empty or whitespace
	 */
	if (!is_absolute_path(location))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
				 errmsg("tablespace location must be an absolute path")));

	/*
	 * Check that location isn't too long. Remember that we're going to append
	 * 'PG_XXX/<dboid>/<relid>_<fork>.<nnn>'.  FYI, we never actually
	 * reference the whole path here, but mkdir() uses the first two parts.
	 */
	if (strlen(location) + 1 + strlen(TABLESPACE_VERSION_DIRECTORY) + 1 +
	  OIDCHARS + 1 + OIDCHARS + 1 + FORKNAMECHARS + 1 + OIDCHARS > MAXPGPATH)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
				 errmsg("tablespace location \"%s\" is too long",
						location)));

	/* Warn if the tablespace is in the data directory. */
	if (path_is_prefix_of_path(DataDir, location))
		ereport(WARNING,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
				 errmsg("tablespace location should not be inside the data directory")));

	/*
	 * Disallow creation of tablespaces named "pg_xxx"; we reserve this
	 * namespace for system purposes.
	 */
	if (!allowSystemTableMods && IsReservedName(stmt->tablespacename))
		ereport(ERROR,
				(errcode(ERRCODE_RESERVED_NAME),
				 errmsg("unacceptable tablespace name \"%s\"",
						stmt->tablespacename),
		errdetail("The prefix \"pg_\" is reserved for system tablespaces.")));

	/*
	 * Check that there is no other tablespace by this name.  (The unique
	 * index would catch this anyway, but might as well give a friendlier
	 * message.)
	 */
	if (OidIsValid(get_tablespace_oid(stmt->tablespacename, true)))
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_OBJECT),
				 errmsg("tablespace \"%s\" already exists",
						stmt->tablespacename)));

	/*
	 * Insert tuple into pg_tablespace.  The purpose of doing this first is to
	 * lock the proposed tablename against other would-be creators. The
	 * insertion will roll back if we find problems below.
	 */
	rel = heap_open(TableSpaceRelationId, RowExclusiveLock);

	MemSet(nulls, false, sizeof(nulls));

	values[Anum_pg_tablespace_spcname - 1] =
		DirectFunctionCall1(namein, CStringGetDatum(stmt->tablespacename));
	values[Anum_pg_tablespace_spcowner - 1] =
		ObjectIdGetDatum(ownerId);
	nulls[Anum_pg_tablespace_spcacl - 1] = true;

	/* Generate new proposed spcoptions (text array) */
	newOptions = transformRelOptions((Datum) 0,
									 stmt->options,
									 NULL, NULL, false, false);
	(void) tablespace_reloptions(newOptions, true);
	if (newOptions != (Datum) 0)
		values[Anum_pg_tablespace_spcoptions - 1] = newOptions;
	else
		nulls[Anum_pg_tablespace_spcoptions - 1] = true;

	tuple = heap_form_tuple(rel->rd_att, values, nulls);

	tablespaceoid = simple_heap_insert(rel, tuple);

	CatalogUpdateIndexes(rel, tuple);

	heap_freetuple(tuple);

	/* Record dependency on owner */
	recordDependencyOnOwner(TableSpaceRelationId, tablespaceoid, ownerId);

	/* Post creation hook for new tablespace */
	InvokeObjectPostCreateHook(TableSpaceRelationId, tablespaceoid, 0);

	create_tablespace_directories(location, tablespaceoid);

	/* Record the filesystem change in XLOG */
	{
		xl_tblspc_create_rec xlrec;

		xlrec.ts_id = tablespaceoid;

		XLogBeginInsert();
		XLogRegisterData((char *) &xlrec,
						 offsetof(xl_tblspc_create_rec, ts_path));
		XLogRegisterData((char *) location, strlen(location) + 1);

		(void) XLogInsert(RM_TBLSPC_ID, XLOG_TBLSPC_CREATE);
	}

	/*
	 * Force synchronous commit, to minimize the window between creating the
	 * symlink on-disk and marking the transaction committed.  It's not great
	 * that there is any window at all, but definitely we don't want to make
	 * it larger than necessary.
	 */
	ForceSyncCommit();

	pfree(location);

	/* We keep the lock on pg_tablespace until commit */
	heap_close(rel, NoLock);

	return tablespaceoid;
#else							/* !HAVE_SYMLINK */
	ereport(ERROR,
			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
			 errmsg("tablespaces are not supported on this platform")));
	return InvalidOid;			/* keep compiler quiet */
#endif   /* HAVE_SYMLINK */
}