Arrange for the postmaster (and standalone backends, initdb, etc) to

chdir into PGDATA and subsequently use relative paths instead of absolute
paths to access all files under PGDATA.  This seems to give a small
performance improvement, and it should make the system more robust
against naive DBAs doing things like moving a database directory that
has a live postmaster in it.  Per recent discussion.

contrib/dbsize/dbsize.c

@@ -5,7 +5,7 @@
  * Copyright (c) 2002-2005, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/contrib/dbsize/dbsize.c,v 1.18 2005/06/19 21:34:00 tgl Exp $
+ *	  $PostgreSQL: pgsql/contrib/dbsize/dbsize.c,v 1.19 2005/07/04 04:51:43 tgl Exp $
  *
  */
 
@@ -24,9 +24,6 @@
 #include "utils/syscache.h"
 
 
-/* hack to make it compile under Win32 */
-extern DLLIMPORT char *DataDir;
-
 Datum pg_tablespace_size(PG_FUNCTION_ARGS);
 Datum pg_database_size(PG_FUNCTION_ARGS);
 Datum pg_relation_size(PG_FUNCTION_ARGS);
@@ -91,11 +88,11 @@ calculate_database_size(Oid dbOid)
 	/* Shared storage in pg_global is not counted */
 
 	/* Include pg_default storage */
-	snprintf(pathname, MAXPGPATH, "%s/base/%u", DataDir, dbOid);
+	snprintf(pathname, MAXPGPATH, "base/%u", dbOid);
 	totalsize += db_dir_size(pathname);
 
 	/* Scan the non-default tablespaces */
-	snprintf(pathname, MAXPGPATH, "%s/pg_tblspc", DataDir);
+	snprintf(pathname, MAXPGPATH, "pg_tblspc");
 	dirdesc = AllocateDir(pathname);
 
 	while ((direntry = ReadDir(dirdesc, pathname)) != NULL)
@@ -104,8 +101,8 @@ calculate_database_size(Oid dbOid)
 			strcmp(direntry->d_name, "..") == 0)
 		    continue;
 
-		snprintf(pathname, MAXPGPATH, "%s/pg_tblspc/%s/%u",
-				 DataDir, direntry->d_name, dbOid);
+		snprintf(pathname, MAXPGPATH, "pg_tblspc/%s/%u",
+				 direntry->d_name, dbOid);
 		totalsize += db_dir_size(pathname);
 	}
 
@@ -134,11 +131,11 @@ pg_tablespace_size(PG_FUNCTION_ARGS)
     struct dirent *direntry;
 
 	if (tblspcOid == DEFAULTTABLESPACE_OID)
-	    snprintf(tblspcPath, MAXPGPATH, "%s/base", DataDir);
+	    snprintf(tblspcPath, MAXPGPATH, "base");
 	else if (tblspcOid == GLOBALTABLESPACE_OID)
-	    snprintf(tblspcPath, MAXPGPATH, "%s/global", DataDir);
+	    snprintf(tblspcPath, MAXPGPATH, "global");
 	else
-		snprintf(tblspcPath, MAXPGPATH, "%s/pg_tblspc/%u", DataDir, tblspcOid);
+		snprintf(tblspcPath, MAXPGPATH, "pg_tblspc/%u", tblspcOid);
 
 	dirdesc = AllocateDir(tblspcPath);
 
@@ -208,12 +205,12 @@ calculate_relation_size(Oid tblspcOid, Oid relnodeOid)
 		tblspcOid = MyDatabaseTableSpace;
 
 	if (tblspcOid == DEFAULTTABLESPACE_OID)
-	    snprintf(dirpath, MAXPGPATH, "%s/base/%u", DataDir, MyDatabaseId);
+	    snprintf(dirpath, MAXPGPATH, "base/%u", MyDatabaseId);
 	else if (tblspcOid == GLOBALTABLESPACE_OID)
-	    snprintf(dirpath, MAXPGPATH, "%s/global", DataDir);
+	    snprintf(dirpath, MAXPGPATH, "global");
 	else
-	    snprintf(dirpath, MAXPGPATH, "%s/pg_tblspc/%u/%u",
-				 DataDir, tblspcOid, MyDatabaseId);
+	    snprintf(dirpath, MAXPGPATH, "pg_tblspc/%u/%u",
+				 tblspcOid, MyDatabaseId);
 
 	for (segcount = 0 ;; segcount++)
 	{

src/backend/access/transam/slru.c

@@ -48,7 +48,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/slru.c,v 1.25 2005/06/19 21:34:01 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/slru.c,v 1.26 2005/07/04 04:51:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -190,7 +190,7 @@ SimpleLruInit(SlruCtl ctl, const char *name,
 	 */
 	ctl->shared = shared;
 	ctl->do_fsync = true;		/* default behavior */
-	snprintf(ctl->Dir, MAXPGPATH, "%s/%s", DataDir, subdir);
+	StrNCpy(ctl->Dir, subdir, sizeof(ctl->Dir));
 }
 
 /*

src/backend/access/transam/twophase.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *		$PostgreSQL: pgsql/src/backend/access/transam/twophase.c,v 1.7 2005/06/28 05:08:51 tgl Exp $
+ *		$PostgreSQL: pgsql/src/backend/access/transam/twophase.c,v 1.8 2005/07/04 04:51:44 tgl Exp $
  *
  * NOTES
  *		Each global transaction is associated with a global transaction
@@ -661,7 +661,7 @@ TwoPhaseGetDummyProc(TransactionId xid)
 /************************************************************************/
 
 #define TwoPhaseFilePath(path, xid) \
-	snprintf(path, MAXPGPATH, "%s/%s/%08X", DataDir, TWOPHASE_DIR, xid)
+	snprintf(path, MAXPGPATH, TWOPHASE_DIR "/%08X", xid)
 
 /*
  * 2PC state file format:
@@ -1434,14 +1434,11 @@ PrescanPreparedTransactions(void)
 {
 	TransactionId origNextXid = ShmemVariableCache->nextXid;
 	TransactionId result = origNextXid;
-	char	dir[MAXPGPATH];
 	DIR		*cldir;
 	struct dirent *clde;
 
-	snprintf(dir, MAXPGPATH, "%s/%s", DataDir, TWOPHASE_DIR);
-
-	cldir = AllocateDir(dir);
-	while ((clde = ReadDir(cldir, dir)) != NULL)
+	cldir = AllocateDir(TWOPHASE_DIR);
+	while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
 	{
 		if (strlen(clde->d_name) == 8 &&
 			strspn(clde->d_name, "0123456789ABCDEF") == 8)
@@ -1540,7 +1537,7 @@ RecoverPreparedTransactions(void)
 	DIR		*cldir;
 	struct dirent *clde;
 
-	snprintf(dir, MAXPGPATH, "%s/%s", DataDir, TWOPHASE_DIR);
+	snprintf(dir, MAXPGPATH, "%s", TWOPHASE_DIR);
 
 	cldir = AllocateDir(dir);
 	while ((clde = ReadDir(cldir, dir)) != NULL)

src/backend/bootstrap/bootstrap.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/bootstrap/bootstrap.c,v 1.204 2005/05/06 17:24:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/bootstrap/bootstrap.c,v 1.205 2005/07/04 04:51:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -365,15 +365,17 @@ BootstrapMain(int argc, char *argv[])
 	Assert(DataDir);
 	ValidatePgVersion(DataDir);
 
+	/* Change into DataDir (if under postmaster, should be done already) */
+	if (!IsUnderPostmaster)
+		ChangeToDataDir();
+
 	/* If standalone, create lockfile for data directory */
 	if (!IsUnderPostmaster)
-		CreateDataDirLockFile(DataDir, false);
+		CreateDataDirLockFile(false);
 
 	SetProcessingMode(BootstrapProcessing);
 	IgnoreSystemIndexes(true);
 
-	XLOGPathInit();
-
 	BaseInit();
 
 	/* needed to get LWLocks */

src/backend/catalog/catalog.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.61 2005/05/10 22:27:29 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.62 2005/07/04 04:51:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,26 +41,26 @@ relpath(RelFileNode rnode)
 	{
 		/* Shared system relations live in {datadir}/global */
 		Assert(rnode.dbNode == 0);
-		pathlen = strlen(DataDir) + 8 + OIDCHARS + 1;
+		pathlen = 7 + OIDCHARS + 1;
 		path = (char *) palloc(pathlen);
-		snprintf(path, pathlen, "%s/global/%u",
-				 DataDir, rnode.relNode);
+		snprintf(path, pathlen, "global/%u",
+				 rnode.relNode);
 	}
 	else if (rnode.spcNode == DEFAULTTABLESPACE_OID)
 	{
 		/* The default tablespace is {datadir}/base */
-		pathlen = strlen(DataDir) + 6 + OIDCHARS + 1 + OIDCHARS + 1;
+		pathlen = 5 + OIDCHARS + 1 + OIDCHARS + 1;
 		path = (char *) palloc(pathlen);
-		snprintf(path, pathlen, "%s/base/%u/%u",
-				 DataDir, rnode.dbNode, rnode.relNode);
+		snprintf(path, pathlen, "base/%u/%u",
+				 rnode.dbNode, rnode.relNode);
 	}
 	else
 	{
 		/* All other tablespaces are accessed via symlinks */
-		pathlen = strlen(DataDir) + 11 + OIDCHARS + 1 + OIDCHARS + 1 + OIDCHARS + 1;
+		pathlen = 10 + OIDCHARS + 1 + OIDCHARS + 1 + OIDCHARS + 1;
 		path = (char *) palloc(pathlen);
-		snprintf(path, pathlen, "%s/pg_tblspc/%u/%u/%u",
-				 DataDir, rnode.spcNode, rnode.dbNode, rnode.relNode);
+		snprintf(path, pathlen, "pg_tblspc/%u/%u/%u",
+				 rnode.spcNode, rnode.dbNode, rnode.relNode);
 	}
 	return path;
 }
@@ -82,26 +82,25 @@ GetDatabasePath(Oid dbNode, Oid spcNode)
 	{
 		/* Shared system relations live in {datadir}/global */
 		Assert(dbNode == 0);
-		pathlen = strlen(DataDir) + 7 + 1;
+		pathlen = 6 + 1;
 		path = (char *) palloc(pathlen);
-		snprintf(path, pathlen, "%s/global",
-				 DataDir);
+		snprintf(path, pathlen, "global");
 	}
 	else if (spcNode == DEFAULTTABLESPACE_OID)
 	{
 		/* The default tablespace is {datadir}/base */
-		pathlen = strlen(DataDir) + 6 + OIDCHARS + 1;
+		pathlen = 5 + OIDCHARS + 1;
 		path = (char *) palloc(pathlen);
-		snprintf(path, pathlen, "%s/base/%u",
-				 DataDir, dbNode);
+		snprintf(path, pathlen, "base/%u",
+				 dbNode);
 	}
 	else
 	{
 		/* All other tablespaces are accessed via symlinks */
-		pathlen = strlen(DataDir) + 11 + OIDCHARS + 1 + OIDCHARS + 1;
+		pathlen = 10 + OIDCHARS + 1 + OIDCHARS + 1;
 		path = (char *) palloc(pathlen);
-		snprintf(path, pathlen, "%s/pg_tblspc/%u/%u",
-				 DataDir, spcNode, dbNode);
+		snprintf(path, pathlen, "pg_tblspc/%u/%u",
+				 spcNode, dbNode);
 	}
 	return path;
 }

src/backend/commands/tablespace.c

@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.23 2005/06/28 05:08:54 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.24 2005/07/04 04:51:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -338,8 +338,8 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 	/*
 	 * All seems well, create the symlink
 	 */
-	linkloc = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
-	sprintf(linkloc, "%s/pg_tblspc/%u", DataDir, tablespaceoid);
+	linkloc = (char *) palloc(10 + 10 + 1);
+	sprintf(linkloc, "pg_tblspc/%u", tablespaceoid);
 
 	if (symlink(location, linkloc) < 0)
 		ereport(ERROR,
@@ -491,8 +491,8 @@ remove_tablespace_directories(Oid tablespaceoid, bool redo)
 	char	   *subfile;
 	struct stat st;
 
-	location = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
-	sprintf(location, "%s/pg_tblspc/%u", DataDir, tablespaceoid);
+	location = (char *) palloc(10 + 10 + 1);
+	sprintf(location, "pg_tblspc/%u", tablespaceoid);
 
 	/*
 	 * Check if the tablespace still contains any files.  We try to rmdir
@@ -989,8 +989,8 @@ tblspc_redo(XLogRecPtr lsn, XLogRecord *record)
 		set_short_version(location);
 
 		/* Create the symlink if not already present */
-		linkloc = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
-		sprintf(linkloc, "%s/pg_tblspc/%u", DataDir, xlrec->ts_id);
+		linkloc = (char *) palloc(10 + 10 + 1);
+		sprintf(linkloc, "pg_tblspc/%u", xlrec->ts_id);
 
 		if (symlink(location, linkloc) < 0)
 		{

src/backend/libpq/be-secure.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.57 2005/06/02 21:03:17 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.58 2005/07/04 04:51:46 tgl Exp $
  *
  *	  Since the server static private key ($DataDir/server.key)
  *	  will normally be stored unencrypted so that the database
@@ -100,6 +100,11 @@
 
 
 #ifdef USE_SSL
+
+#define ROOT_CERT_FILE			"root.crt"
+#define SERVER_CERT_FILE		"server.crt"
+#define SERVER_PRIVATE_KEY_FILE	"server.key"
+
 static DH  *load_dh_file(int keylength);
 static DH  *load_dh_buffer(const char *, size_t);
 static DH  *tmp_dh_cb(SSL *s, int is_export, int keylength);
@@ -500,7 +505,7 @@ load_dh_file(int keylength)
 	int			codes;
 
 	/* attempt to open file.  It's not an error if it doesn't exist. */
-	snprintf(fnbuf, sizeof(fnbuf), "%s/dh%d.pem", DataDir, keylength);
+	snprintf(fnbuf, sizeof(fnbuf), "dh%d.pem", keylength);
 	if ((fp = fopen(fnbuf, "r")) == NULL)
 		return NULL;
 
@@ -710,7 +715,6 @@ info_cb(const SSL *ssl, int type, int args)
 static int
 initialize_SSL(void)
 {
-	char		fnbuf[MAXPGPATH];
 	struct stat buf;
 
 	if (!SSL_context)
@@ -726,19 +730,19 @@ initialize_SSL(void)
 		/*
 		 * Load and verify certificate and private key
 		 */
-		snprintf(fnbuf, sizeof(fnbuf), "%s/server.crt", DataDir);
-		if (!SSL_CTX_use_certificate_file(SSL_context, fnbuf, SSL_FILETYPE_PEM))
+		if (!SSL_CTX_use_certificate_file(SSL_context,
+										  SERVER_CERT_FILE,
+										  SSL_FILETYPE_PEM))
 			ereport(FATAL,
 					(errcode(ERRCODE_CONFIG_FILE_ERROR),
 			  errmsg("could not load server certificate file \"%s\": %s",
-					 fnbuf, SSLerrmessage())));
+					 SERVER_CERT_FILE, SSLerrmessage())));
 
-		snprintf(fnbuf, sizeof(fnbuf), "%s/server.key", DataDir);
-		if (stat(fnbuf, &buf) == -1)
+		if (stat(SERVER_PRIVATE_KEY_FILE, &buf) == -1)
 			ereport(FATAL,
 					(errcode_for_file_access(),
 				   errmsg("could not access private key file \"%s\": %m",
-						  fnbuf)));
+						  SERVER_PRIVATE_KEY_FILE)));
 
 		/*
 		 * Require no public access to key file.
@@ -754,14 +758,16 @@ initialize_SSL(void)
 			ereport(FATAL,
 					(errcode(ERRCODE_CONFIG_FILE_ERROR),
 				  errmsg("unsafe permissions on private key file \"%s\"",
-						 fnbuf),
+						 SERVER_PRIVATE_KEY_FILE),
 					 errdetail("File must be owned by the database user and must have no permissions for \"group\" or \"other\".")));
 #endif
 
-		if (!SSL_CTX_use_PrivateKey_file(SSL_context, fnbuf, SSL_FILETYPE_PEM))
+		if (!SSL_CTX_use_PrivateKey_file(SSL_context,
+										 SERVER_PRIVATE_KEY_FILE,
+										 SSL_FILETYPE_PEM))
 			ereport(FATAL,
 					(errmsg("could not load private key file \"%s\": %s",
-							fnbuf, SSLerrmessage())));
+							SERVER_PRIVATE_KEY_FILE, SSLerrmessage())));
 
 		if (!SSL_CTX_check_private_key(SSL_context))
 			ereport(FATAL,
@@ -780,13 +786,12 @@ initialize_SSL(void)
 	/*
 	 * Require and check client certificates only if we have a root.crt file.
 	 */
-	snprintf(fnbuf, sizeof(fnbuf), "%s/root.crt", DataDir);
-	if (!SSL_CTX_load_verify_locations(SSL_context, fnbuf, NULL))
+	if (!SSL_CTX_load_verify_locations(SSL_context, ROOT_CERT_FILE, NULL))
 	{
 		/* Not fatal - we do not require client certificates */
 		ereport(LOG,
 				(errmsg("could not load root certificate file \"%s\": %s",
-						fnbuf, SSLerrmessage()),
+						ROOT_CERT_FILE, SSLerrmessage()),
 				 errdetail("Will not verify client certificates.")));
 	}
 	else

src/backend/postmaster/pgarch.c

@@ -19,7 +19,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/pgarch.c,v 1.16 2005/06/19 21:34:01 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/pgarch.c,v 1.17 2005/07/04 04:51:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -248,9 +248,6 @@ PgArchiverMain(int argc, char *argv[])
 	init_ps_display("archiver process", "", "");
 	set_ps_display("");
 
-	/* Init XLOG file paths --- needed in EXEC_BACKEND case */
-	XLOGPathInit();
-
 	pgarch_MainLoop();
 
 	exit(0);
@@ -400,7 +397,7 @@ pgarch_archiveXlog(char *xlog)
 	const char *sp;
 	int			rc;
 
-	snprintf(pathname, MAXPGPATH, "%s/%s", XLogDir, xlog);
+	snprintf(pathname, MAXPGPATH, XLOGDIR "/%s", xlog);
 
 	/*
 	 * construct the command to be executed
@@ -502,7 +499,7 @@ pgarch_readyXlog(char *xlog)
 	struct dirent *rlde;
 	bool		found = false;
 
-	snprintf(XLogArchiveStatusDir, MAXPGPATH, "%s/archive_status", XLogDir);
+	snprintf(XLogArchiveStatusDir, MAXPGPATH, XLOGDIR "/archive_status");
 	rldir = AllocateDir(XLogArchiveStatusDir);
 	if (rldir == NULL)
 		ereport(ERROR,

src/backend/postmaster/pgstat.c

@@ -13,7 +13,7 @@
  *
  *	Copyright (c) 2001-2005, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.98 2005/06/29 22:51:55 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.99 2005/07/04 04:51:47 tgl Exp $
  * ----------
  */
 #include "postgres.h"
@@ -54,12 +54,11 @@
 
 
 /* ----------
- * Paths for the statistics files. The %s is replaced with the
- * installation's $PGDATA.
+ * Paths for the statistics files (relative to installation's $PGDATA).
  * ----------
  */
-#define PGSTAT_STAT_FILENAME	"%s/global/pgstat.stat"
-#define PGSTAT_STAT_TMPFILE		"%s/global/pgstat.tmp.%d"
+#define PGSTAT_STAT_FILENAME	"global/pgstat.stat"
+#define PGSTAT_STAT_TMPFILE		"global/pgstat.tmp"
 
 /* ----------
  * Timer definitions.
@@ -134,9 +133,6 @@ static HTAB *pgStatBeDead = NULL;
 static PgStat_StatBeEntry *pgStatBeTable = NULL;
 static int	pgStatNumBackends = 0;
 
-static char pgStat_fname[MAXPGPATH];
-static char pgStat_tmpfname[MAXPGPATH];
-
 
 /* ----------
  * Local function forward declarations
@@ -220,21 +216,12 @@ pgstat_init(void)
 		pgstat_collect_blocklevel)
 		pgstat_collect_startcollector = true;
 
-	/*
-	 * Initialize the filename for the status reports.	(In the
-	 * EXEC_BACKEND case, this only sets the value in the postmaster.  The
-	 * collector subprocess will recompute the value for itself, and
-	 * individual backends must do so also if they want to access the
-	 * file.)
-	 */
-	snprintf(pgStat_fname, MAXPGPATH, PGSTAT_STAT_FILENAME, DataDir);
-
 	/*
 	 * If we don't have to start a collector or should reset the collected
-	 * statistics on postmaster start, simply remove the file.
+	 * statistics on postmaster start, simply remove the stats file.
 	 */
 	if (!pgstat_collect_startcollector || pgstat_collect_resetonpmstart)
-		unlink(pgStat_fname);
+		unlink(PGSTAT_STAT_FILENAME);
 
 	/*
 	 * Nothing else required if collector will not get started
@@ -1470,14 +1457,6 @@ PgstatCollectorMain(int argc, char *argv[])
 	init_ps_display("stats collector process", "", "");
 	set_ps_display("");
 
-	/*
-	 * Initialize filenames needed for status reports.
-	 */
-	snprintf(pgStat_fname, MAXPGPATH, PGSTAT_STAT_FILENAME, DataDir);
-	/* tmpfname need only be set correctly in this process */
-	snprintf(pgStat_tmpfname, MAXPGPATH, PGSTAT_STAT_TMPFILE,
-			 DataDir, (int)getpid());
-
 	/*
 	 * Arrange to write the initial status file right away
 	 */
@@ -2161,13 +2140,13 @@ pgstat_write_statsfile(void)
 	/*
 	 * Open the statistics temp file to write out the current values.
 	 */
-	fpout = fopen(pgStat_tmpfname, PG_BINARY_W);
+	fpout = fopen(PGSTAT_STAT_TMPFILE, PG_BINARY_W);
 	if (fpout == NULL)
 	{
 		ereport(LOG,
 				(errcode_for_file_access(),
 			errmsg("could not open temporary statistics file \"%s\": %m",
-				   pgStat_tmpfname)));
+				   PGSTAT_STAT_TMPFILE)));
 		return;
 	}
 
@@ -2276,16 +2255,16 @@ pgstat_write_statsfile(void)
 		ereport(LOG,
 				(errcode_for_file_access(),
 		   errmsg("could not close temporary statistics file \"%s\": %m",
-				  pgStat_tmpfname)));
+				  PGSTAT_STAT_TMPFILE)));
 	}
 	else
 	{
-		if (rename(pgStat_tmpfname, pgStat_fname) < 0)
+		if (rename(PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME) < 0)
 		{
 			ereport(LOG,
 					(errcode_for_file_access(),
 					 errmsg("could not rename temporary statistics file \"%s\" to \"%s\": %m",
-							pgStat_tmpfname, pgStat_fname)));
+							PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME)));
 		}
 	}
 
@@ -2376,24 +2355,12 @@ pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
 	if (betab != NULL)
 		*betab = NULL;
 
-	/*
-	 * In EXEC_BACKEND case, we won't have inherited pgStat_fname from
-	 * postmaster, so compute it first time through.
-	 */
-#ifdef EXEC_BACKEND
-	if (pgStat_fname[0] == '\0')
-	{
-		Assert(DataDir != NULL);
-		snprintf(pgStat_fname, MAXPGPATH, PGSTAT_STAT_FILENAME, DataDir);
-	}
-#endif
-
 	/*
 	 * Try to open the status file. If it doesn't exist, the backends
 	 * simply return zero for anything and the collector simply starts
 	 * from scratch with empty counters.
 	 */
-	if ((fpin = AllocateFile(pgStat_fname, PG_BINARY_R)) == NULL)
+	if ((fpin = AllocateFile(PGSTAT_STAT_FILENAME, PG_BINARY_R)) == NULL)
 		return;
 
 	/*

src/backend/postmaster/postmaster.c

@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.457 2005/06/30 10:02:22 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.458 2005/07/04 04:51:47 tgl Exp $
  *
  * NOTES
  *
@@ -585,6 +585,15 @@ PostmasterMain(int argc, char *argv[])
 		ExitPostmaster(1);
 	}
 
+#ifdef EXEC_BACKEND
+	/* Locate executable backend before we change working directory */
+	if (find_other_exec(argv[0], "postgres", PG_VERSIONSTR,
+						postgres_exec_path) < 0)
+		ereport(FATAL,
+			 (errmsg("%s: could not locate matching postgres executable",
+					 progname)));
+#endif
+
 	/*
 	 * Locate the proper configuration files and data directory, and
 	 * read postgresql.conf for the first time.
@@ -595,6 +604,9 @@ PostmasterMain(int argc, char *argv[])
 	/* Verify that DataDir looks reasonable */
 	checkDataDir();
 
+	/* And switch working directory into it */
+	ChangeToDataDir();
+
 	/*
 	 * Check for invalid combinations of GUC settings.
 	 */
@@ -650,14 +662,6 @@ PostmasterMain(int argc, char *argv[])
 		 (errmsg_internal("-----------------------------------------")));
 	}
 
-#ifdef EXEC_BACKEND
-	if (find_other_exec(argv[0], "postgres", PG_VERSIONSTR,
-						postgres_exec_path) < 0)
-		ereport(FATAL,
-			 (errmsg("%s: could not locate matching postgres executable",
-					 progname)));
-#endif
-
 	/*
 	 * Initialize SSL library, if specified.
 	 */
@@ -691,7 +695,7 @@ PostmasterMain(int argc, char *argv[])
 	 * :-(). For the same reason, it's best to grab the TCP socket(s)
 	 * before the Unix socket.
 	 */
-	CreateDataDirLockFile(DataDir, true);
+	CreateDataDirLockFile(true);
 
 	/*
 	 * Remove old temporary files.	At this point there can be no other
@@ -786,8 +790,6 @@ PostmasterMain(int argc, char *argv[])
 		ereport(FATAL,
 				(errmsg("no socket created for listening")));
 
-	XLOGPathInit();
-
 	/*
 	 * Set up shared memory and semaphores.
 	 */
@@ -2866,20 +2868,16 @@ internal_forkexec(int argc, char *argv[], Port *port)
 		return -1;				/* log made by save_backend_variables */
 
 	/* Calculate name for temp file */
-	Assert(DataDir);
-	snprintf(tmpfilename, MAXPGPATH, "%s/%s/%s.backend_var.%d.%lu",
-			 DataDir, PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
+	snprintf(tmpfilename, MAXPGPATH, "%s/%s.backend_var.%d.%lu",
+			 PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
 			 MyProcPid, ++tmpBackendFileNum);
 
 	/* Open file */
 	fp = AllocateFile(tmpfilename, PG_BINARY_W);
 	if (!fp)
 	{
-		/* As per OpenTemporaryFile... */
-		char		dirname[MAXPGPATH];
-
-		snprintf(dirname, MAXPGPATH, "%s/%s", DataDir, PG_TEMP_FILES_DIR);
-		mkdir(dirname, S_IRWXU);
+		/* As in OpenTemporaryFile, try to make the temp-file directory */
+		mkdir(PG_TEMP_FILES_DIR, S_IRWXU);
 
 		fp = AllocateFile(tmpfilename, PG_BINARY_W);
 		if (!fp)
@@ -3527,15 +3525,14 @@ StartChildProcess(int xlop)
 static bool
 CreateOptsFile(int argc, char *argv[], char *fullprogname)
 {
-	char		filename[MAXPGPATH];
 	FILE	   *fp;
 	int			i;
 
-	snprintf(filename, sizeof(filename), "%s/postmaster.opts", DataDir);
+#define OPTS_FILE	"postmaster.opts"
 
-	if ((fp = fopen(filename, "w")) == NULL)
+	if ((fp = fopen(OPTS_FILE, "w")) == NULL)
 	{
-		elog(LOG, "could not create file \"%s\": %m", filename);
+		elog(LOG, "could not create file \"%s\": %m", OPTS_FILE);
 		return false;
 	}
 
@@ -3546,7 +3543,7 @@ CreateOptsFile(int argc, char *argv[], char *fullprogname)
 
 	if (fclose(fp))
 	{
-		elog(LOG, "could not write file \"%s\": %m", filename);
+		elog(LOG, "could not write file \"%s\": %m", OPTS_FILE);
 		return false;
 	}
 

src/backend/postmaster/syslogger.c

@@ -18,7 +18,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.15 2005/04/19 03:13:59 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/syslogger.c,v 1.16 2005/07/04 04:51:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -422,17 +422,9 @@ SysLogger_Start(void)
 #endif
 
 	/*
-	 * create log directory if not present; ignore errors
+	 * Create log directory if not present; ignore errors
 	 */
-	if (is_absolute_path(Log_directory))
-		mkdir(Log_directory, 0700);
-	else
-	{
-		filename = palloc(MAXPGPATH);
-		snprintf(filename, MAXPGPATH, "%s/%s", DataDir, Log_directory);
-		mkdir(filename, 0700);
-		pfree(filename);
-	}
+	mkdir(Log_directory, 0700);
 
 	/*
 	 * The initial logfile is created right in the postmaster, to verify
@@ -823,10 +815,7 @@ logfile_getname(pg_time_t timestamp)
 
 	filename = palloc(MAXPGPATH);
 
-	if (is_absolute_path(Log_directory))
-		snprintf(filename, MAXPGPATH, "%s/", Log_directory);
-	else
-		snprintf(filename, MAXPGPATH, "%s/%s/", DataDir, Log_directory);
+	snprintf(filename, MAXPGPATH, "%s/", Log_directory);
 
 	len = strlen(filename);
 

src/backend/storage/file/fd.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.117 2005/06/19 21:34:02 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.118 2005/07/04 04:51:48 tgl Exp $
  *
  * NOTES:
  *
@@ -224,8 +224,7 @@ static File AllocateVfd(void);
 static void FreeVfd(File file);
 
 static int	FileAccess(File file);
-static File fileNameOpenFile(FileName fileName, int fileFlags, int fileMode);
-static char *filepath(const char *filename);
+static char *make_database_relative(const char *filename);
 static void AtProcExit_Files(int code, Datum arg);
 static void CleanupTempFiles(bool isProcExit);
 static void RemovePgTempFilesInDir(const char *tmpdirname);
@@ -699,34 +698,20 @@ FreeVfd(File file)
 	VfdCache[0].nextFree = file;
 }
 
-/* filepath()
- * Convert given pathname to absolute.
+/*
+ * make_database_relative()
+ *		Prepend DatabasePath to the given file name.
  *
  * Result is a palloc'd string.
- *
- * (Generally, this isn't actually necessary, considering that we
- * should be cd'd into the database directory.  Presently it is only
- * necessary to do it in "bootstrap" mode.	Maybe we should change
- * bootstrap mode to do the cd, and save a few cycles/bytes here.)
  */
 static char *
-filepath(const char *filename)
+make_database_relative(const char *filename)
 {
 	char	   *buf;
 
-	/* Not an absolute path name? Then fill in with database path... */
-	if (!is_absolute_path(filename))
-	{
-		buf = (char *) palloc(strlen(DatabasePath) + strlen(filename) + 2);
-		sprintf(buf, "%s/%s", DatabasePath, filename);
-	}
-	else
-		buf = pstrdup(filename);
-
-#ifdef FILEDEBUG
-	printf("filepath: path is %s\n", buf);
-#endif
-
+	Assert(!is_absolute_path(filename));
+	buf = (char *) palloc(strlen(DatabasePath) + strlen(filename) + 2);
+	sprintf(buf, "%s/%s", DatabasePath, filename);
 	return buf;
 }
 
@@ -779,16 +764,21 @@ FileInvalidate(File file)
 }
 #endif
 
-static File
-fileNameOpenFile(FileName fileName,
-				 int fileFlags,
-				 int fileMode)
+/*
+ * open a file in an arbitrary directory
+ *
+ * NB: if the passed pathname is relative (which it usually is),
+ * it will be interpreted relative to the process' working directory
+ * (which should always be $PGDATA when this code is running).
+ */
+File
+PathNameOpenFile(FileName fileName, int fileFlags, int fileMode)
 {
 	char	   *fnamecopy;
 	File		file;
 	Vfd		   *vfdP;
 
-	DO_DB(elog(LOG, "fileNameOpenFile: %s %x %o",
+	DO_DB(elog(LOG, "PathNameOpenFile: %s %x %o",
 			   fileName, fileFlags, fileMode));
 
 	/*
@@ -818,7 +808,7 @@ fileNameOpenFile(FileName fileName,
 		return -1;
 	}
 	++nfile;
-	DO_DB(elog(LOG, "fileNameOpenFile: success %d",
+	DO_DB(elog(LOG, "PathNameOpenFile: success %d",
 			   vfdP->fd));
 
 	Insert(file);
@@ -834,7 +824,10 @@ fileNameOpenFile(FileName fileName,
 }
 
 /*
- * open a file in the database directory ($PGDATA/base/...)
+ * open a file in the database directory ($PGDATA/base/DIROID/)
+ *
+ * The passed name MUST be a relative path.  Effectively, this
+ * prepends DatabasePath to it and then acts like PathNameOpenFile.
  */
 File
 FileNameOpenFile(FileName fileName, int fileFlags, int fileMode)
@@ -842,21 +835,12 @@ FileNameOpenFile(FileName fileName, int fileFlags, int fileMode)
 	File		fd;
 	char	   *fname;
 
-	fname = filepath(fileName);
-	fd = fileNameOpenFile(fname, fileFlags, fileMode);
+	fname = make_database_relative(fileName);
+	fd = PathNameOpenFile(fname, fileFlags, fileMode);
 	pfree(fname);
 	return fd;
 }
 
-/*
- * open a file in an arbitrary directory
- */
-File
-PathNameOpenFile(FileName fileName, int fileFlags, int fileMode)
-{
-	return fileNameOpenFile(fileName, fileFlags, fileMode);
-}
-
 /*
  * Open a temporary file that will disappear when we close it.
  *
@@ -903,7 +887,7 @@ OpenTemporaryFile(bool interXact)
 		 * just did the same thing.  If it doesn't work then we'll bomb
 		 * out on the second create attempt, instead.
 		 */
-		dirpath = filepath(PG_TEMP_FILES_DIR);
+		dirpath = make_database_relative(PG_TEMP_FILES_DIR);
 		mkdir(dirpath, S_IRWXU);
 		pfree(dirpath);
 
@@ -1568,7 +1552,6 @@ CleanupTempFiles(bool isProcExit)
 void
 RemovePgTempFiles(void)
 {
-	char		db_path[MAXPGPATH];
 	char		temp_path[MAXPGPATH];
 	DIR		   *db_dir;
 	struct dirent *db_de;
@@ -1577,17 +1560,16 @@ RemovePgTempFiles(void)
 	 * Cycle through pgsql_tmp directories for all databases and remove old
 	 * temp files.
 	 */
-	snprintf(db_path, sizeof(db_path), "%s/base", DataDir);
-	db_dir = AllocateDir(db_path);
+	db_dir = AllocateDir("base");
 
-	while ((db_de = ReadDir(db_dir, db_path)) != NULL)
+	while ((db_de = ReadDir(db_dir, "base")) != NULL)
 	{
 		if (strcmp(db_de->d_name, ".") == 0 ||
 			strcmp(db_de->d_name, "..") == 0)
 			continue;
 
-		snprintf(temp_path, sizeof(temp_path), "%s/%s/%s",
-				 db_path, db_de->d_name, PG_TEMP_FILES_DIR);
+		snprintf(temp_path, sizeof(temp_path), "base/%s/%s",
+				 db_de->d_name, PG_TEMP_FILES_DIR);
 		RemovePgTempFilesInDir(temp_path);
 	}
 
@@ -1598,9 +1580,7 @@ RemovePgTempFiles(void)
 	 * level of DataDir as well.
 	 */
 #ifdef EXEC_BACKEND
-	snprintf(temp_path, sizeof(temp_path), "%s/%s",
-			 DataDir, PG_TEMP_FILES_DIR);
-	RemovePgTempFilesInDir(temp_path);
+	RemovePgTempFilesInDir(PG_TEMP_FILES_DIR);
 #endif
 }
 

src/backend/storage/freespace/freespace.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/freespace/freespace.c,v 1.45 2005/05/29 04:23:04 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/freespace/freespace.c,v 1.46 2005/07/04 04:51:48 tgl Exp $
  *
  *
  * NOTES:
@@ -752,20 +752,16 @@ void
 DumpFreeSpaceMap(int code, Datum arg)
 {
 	FILE	   *fp;
-	char		cachefilename[MAXPGPATH];
 	FsmCacheFileHeader header;
 	FSMRelation *fsmrel;
 
 	/* Try to create file */
-	snprintf(cachefilename, sizeof(cachefilename), "%s/%s",
-			 DataDir, FSM_CACHE_FILENAME);
+	unlink(FSM_CACHE_FILENAME);		/* in case it exists w/wrong permissions */
 
-	unlink(cachefilename);		/* in case it exists w/wrong permissions */
-
-	fp = AllocateFile(cachefilename, PG_BINARY_W);
+	fp = AllocateFile(FSM_CACHE_FILENAME, PG_BINARY_W);
 	if (fp == NULL)
 	{
-		elog(LOG, "could not write \"%s\": %m", cachefilename);
+		elog(LOG, "could not write \"%s\": %m", FSM_CACHE_FILENAME);
 		return;
 	}
 
@@ -821,15 +817,15 @@ DumpFreeSpaceMap(int code, Datum arg)
 
 	if (FreeFile(fp))
 	{
-		elog(LOG, "could not write \"%s\": %m", cachefilename);
+		elog(LOG, "could not write \"%s\": %m", FSM_CACHE_FILENAME);
 		/* Remove busted cache file */
-		unlink(cachefilename);
+		unlink(FSM_CACHE_FILENAME);
 	}
 
 	return;
 
 write_failed:
-	elog(LOG, "could not write \"%s\": %m", cachefilename);
+	elog(LOG, "could not write \"%s\": %m", FSM_CACHE_FILENAME);
 
 	/* Clean up */
 	LWLockRelease(FreeSpaceLock);
@@ -837,7 +833,7 @@ write_failed:
 	FreeFile(fp);
 
 	/* Remove busted cache file */
-	unlink(cachefilename);
+	unlink(FSM_CACHE_FILENAME);
 }
 
 /*
@@ -858,19 +854,15 @@ void
 LoadFreeSpaceMap(void)
 {
 	FILE	   *fp;
-	char		cachefilename[MAXPGPATH];
 	FsmCacheFileHeader header;
 	int			relno;
 
 	/* Try to open file */
-	snprintf(cachefilename, sizeof(cachefilename), "%s/%s",
-			 DataDir, FSM_CACHE_FILENAME);
-
-	fp = AllocateFile(cachefilename, PG_BINARY_R);
+	fp = AllocateFile(FSM_CACHE_FILENAME, PG_BINARY_R);
 	if (fp == NULL)
 	{
 		if (errno != ENOENT)
-			elog(LOG, "could not read \"%s\": %m", cachefilename);
+			elog(LOG, "could not read \"%s\": %m", FSM_CACHE_FILENAME);
 		return;
 	}
 
@@ -883,7 +875,7 @@ LoadFreeSpaceMap(void)
 		header.version != FSM_CACHE_VERSION ||
 		header.numRels < 0)
 	{
-		elog(LOG, "bogus file header in \"%s\"", cachefilename);
+		elog(LOG, "bogus file header in \"%s\"", FSM_CACHE_FILENAME);
 		goto read_failed;
 	}
 
@@ -905,7 +897,7 @@ LoadFreeSpaceMap(void)
 			relheader.lastPageCount < 0 ||
 			relheader.storedPages < 0)
 		{
-			elog(LOG, "bogus rel header in \"%s\"", cachefilename);
+			elog(LOG, "bogus rel header in \"%s\"", FSM_CACHE_FILENAME);
 			goto read_failed;
 		}
 
@@ -922,7 +914,7 @@ LoadFreeSpaceMap(void)
 		data = (char *) palloc(len);
 		if (fread(data, 1, len, fp) != len)
 		{
-			elog(LOG, "premature EOF in \"%s\"", cachefilename);
+			elog(LOG, "premature EOF in \"%s\"", FSM_CACHE_FILENAME);
 			pfree(data);
 			goto read_failed;
 		}
@@ -993,7 +985,7 @@ read_failed:
 	FreeFile(fp);
 
 	/* Remove cache file before it can become stale; see notes above */
-	unlink(cachefilename);
+	unlink(FSM_CACHE_FILENAME);
 }
 
 

src/backend/storage/smgr/md.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.116 2005/06/20 18:37:01 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.117 2005/07/04 04:51:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -155,7 +155,7 @@ mdcreate(SMgrRelation reln, bool isRedo)
 
 	path = relpath(reln->smgr_rnode);
 
-	fd = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
+	fd = PathNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
 
 	if (fd < 0)
 	{
@@ -169,7 +169,7 @@ mdcreate(SMgrRelation reln, bool isRedo)
 		 * mdopen)
 		 */
 		if (isRedo || IsBootstrapProcessingMode())
-			fd = FileNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
+			fd = PathNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
 		if (fd < 0)
 		{
 			pfree(path);
@@ -340,7 +340,7 @@ mdopen(SMgrRelation reln, bool allowNotFound)
 
 	path = relpath(reln->smgr_rnode);
 
-	fd = FileNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
+	fd = PathNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
 
 	if (fd < 0)
 	{
@@ -352,7 +352,7 @@ mdopen(SMgrRelation reln, bool allowNotFound)
 		 * (See mdcreate)
 		 */
 		if (IsBootstrapProcessingMode())
-			fd = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
+			fd = PathNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
 		if (fd < 0)
 		{
 			pfree(path);
@@ -879,7 +879,7 @@ _mdfd_openseg(SMgrRelation reln, BlockNumber segno, int oflags)
 		fullpath = path;
 
 	/* open the file */
-	fd = FileNameOpenFile(fullpath, O_RDWR | PG_BINARY | oflags, 0600);
+	fd = PathNameOpenFile(fullpath, O_RDWR | PG_BINARY | oflags, 0600);
 
 	pfree(fullpath);
 

src/backend/tcop/postgres.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.451 2005/06/29 22:51:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.452 2005/07/04 04:51:49 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -2809,8 +2809,6 @@ PostgresMain(int argc, char *argv[], const char *username)
 			errhint("Try \"%s --help\" for more information.", argv[0])));
 		}
 
-		XLOGPathInit();
-
 		BaseInit();
 	}
 	else
@@ -2841,12 +2839,14 @@ PostgresMain(int argc, char *argv[], const char *username)
 		Assert(DataDir);
 		ValidatePgVersion(DataDir);
 
+		/* Change into DataDir (if under postmaster, was done already) */
+		ChangeToDataDir();
+
 		/*
 		 * Create lockfile for data directory.
 		 */
-		CreateDataDirLockFile(DataDir, false);
+		CreateDataDirLockFile(false);
 
-		XLOGPathInit();
 		BaseInit();
 
 		/*

src/backend/utils/adt/misc.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.44 2005/06/19 21:34:02 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.45 2005/07/04 04:51:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -145,10 +145,10 @@ pg_tablespace_databases(PG_FUNCTION_ARGS)
 		fctx = palloc(sizeof(ts_db_fctx));
 
 		/*
-		 * size = path length + tablespace dirname length + 2 dir sep
-		 * chars + oid + terminator
+		 * size = tablespace dirname length + dir sep
+		 * char + oid + terminator
 		 */
-		fctx->location = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
+		fctx->location = (char *) palloc(10 + 10 + 1);
 		if (tablespaceOid == GLOBALTABLESPACE_OID)
 		{
 			fctx->dirdesc = NULL;
@@ -158,10 +158,9 @@ pg_tablespace_databases(PG_FUNCTION_ARGS)
 		else
 		{
 			if (tablespaceOid == DEFAULTTABLESPACE_OID)
-				sprintf(fctx->location, "%s/base", DataDir);
+				sprintf(fctx->location, "base");
 			else
-				sprintf(fctx->location, "%s/pg_tblspc/%u", DataDir,
-						tablespaceOid);
+				sprintf(fctx->location, "pg_tblspc/%u", tablespaceOid);
 
 			fctx->dirdesc = AllocateDir(fctx->location);
 

src/backend/utils/init/flatfiles.c

@@ -23,7 +23,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/utils/init/flatfiles.c,v 1.11 2005/06/29 20:34:15 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/init/flatfiles.c,v 1.12 2005/07/04 04:51:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,9 +50,9 @@
 #include "utils/syscache.h"
 
 
-/* Actual names of the flat files (within $PGDATA/global/) */
-#define DATABASE_FLAT_FILE	"pg_database"
-#define AUTH_FLAT_FILE		"pg_auth"
+/* Actual names of the flat files (within $PGDATA) */
+#define DATABASE_FLAT_FILE	"global/pg_database"
+#define AUTH_FLAT_FILE		"global/pg_auth"
 
 /* Info bits in a flatfiles 2PC record */
 #define FF_BIT_DATABASE	1
@@ -98,41 +98,29 @@ auth_file_update_needed(void)
 
 
 /*
- * database_getflatfilename --- get full pathname of database file
+ * database_getflatfilename --- get pathname of database file
  *
  * Note that result string is palloc'd, and should be freed by the caller.
+ * (This convention is not really needed anymore, since the relative path
+ * is fixed.)
  */
 char *
 database_getflatfilename(void)
 {
-	int			bufsize;
-	char	   *pfnam;
-
-	bufsize = strlen(DataDir) + strlen("/global/") +
-		strlen(DATABASE_FLAT_FILE) + 1;
-	pfnam = (char *) palloc(bufsize);
-	snprintf(pfnam, bufsize, "%s/global/%s", DataDir, DATABASE_FLAT_FILE);
-
-	return pfnam;
+	return pstrdup(DATABASE_FLAT_FILE);
 }
 
 /*
- * auth_getflatfilename --- get full pathname of auth file
+ * auth_getflatfilename --- get pathname of auth file
  *
  * Note that result string is palloc'd, and should be freed by the caller.
+ * (This convention is not really needed anymore, since the relative path
+ * is fixed.)
  */
 char *
 auth_getflatfilename(void)
 {
-	int			bufsize;
-	char	   *pfnam;
-
-	bufsize = strlen(DataDir) + strlen("/global/") +
-		strlen(AUTH_FLAT_FILE) + 1;
-	pfnam = (char *) palloc(bufsize);
-	snprintf(pfnam, bufsize, "%s/global/%s", DataDir, AUTH_FLAT_FILE);
-
-	return pfnam;
+	return pstrdup(AUTH_FLAT_FILE);
 }
 
 

src/backend/utils/init/globals.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/init/globals.c,v 1.95 2004/12/31 22:01:40 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/init/globals.c,v 1.96 2005/07/04 04:51:50 tgl Exp $
  *
  * NOTES
  *	  Globals used all over the place should be declared here and not
@@ -36,13 +36,14 @@ int			MyProcPid;
 struct Port *MyProcPort;
 long		MyCancelKey;
 
+/*
+ * DataDir is the absolute path to the top level of the PGDATA directory tree.
+ * Except during early startup, this is also the server's working directory;
+ * most code therefore can simply use relative paths and not reference DataDir
+ * explicitly.
+ */
 char	   *DataDir = NULL;
 
- /*
-  * The PGDATA directory user says to use, or defaults to via environment
-  * variable.  NULL if no option given and no environment variable set
-  */
-
 char		OutputFileName[MAXPGPATH];	/* debugging output file */
 
 char		my_exec_path[MAXPGPATH];	/* full path to my executable */
@@ -56,11 +57,16 @@ char		postgres_exec_path[MAXPGPATH];		/* full path to backend */
 
 BackendId	MyBackendId = InvalidBackendId;
 
-char	   *DatabasePath = NULL;
 Oid			MyDatabaseId = InvalidOid;
 
 Oid			MyDatabaseTableSpace = InvalidOid;
 
+/*
+ * DatabasePath is the path (relative to DataDir) of my database's
+ * primary directory, ie, its directory in the default tablespace.
+ */
+char	   *DatabasePath = NULL;
+
 pid_t		PostmasterPid = 0;
 
 /*

src/backend/utils/init/miscinit.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/init/miscinit.c,v 1.144 2005/06/28 22:16:45 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/init/miscinit.c,v 1.145 2005/07/04 04:51:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,10 +41,11 @@
 #include "utils/syscache.h"
 
 
+#define DIRECTORY_LOCK_FILE		"postmaster.pid"
+
 ProcessingMode Mode = InitProcessing;
 
-/* Note: we rely on these to initialize as zeroes */
-static char directoryLockFile[MAXPGPATH];
+/* Note: we rely on this to initialize as zeroes */
 static char socketLockFile[MAXPGPATH];
 
 
@@ -177,16 +178,33 @@ SetDataDir(const char *dir)
 	DataDir = new;
 }
 
+/*
+ * Change working directory to DataDir.  Most of the postmaster and backend
+ * code assumes that we are in DataDir so it can use relative paths to access
+ * stuff in and under the data directory.  For convenience during path
+ * setup, however, we don't force the chdir to occur during SetDataDir.
+ */
+void
+ChangeToDataDir(void)
+{
+	AssertState(DataDir);
+
+	if (chdir(DataDir) < 0)
+		ereport(FATAL,
+				(errcode_for_file_access(),
+				 errmsg("could not change directory to \"%s\": %m",
+						DataDir)));
+}
+
 /*
  * If the given pathname isn't already absolute, make it so, interpreting
  * it relative to the current working directory.
  *
  * Also canonicalizes the path.  The result is always a malloc'd copy.
  *
- * Note: it is probably unwise to use this in running backends, since they
- * have chdir'd to a database-specific subdirectory; the results would not be
- * consistent across backends.  Currently this is used only during postmaster
- * or standalone-backend startup.
+ * Note: interpretation of relative-path arguments during postmaster startup
+ * should happen before doing ChangeToDataDir(), else the user will probably
+ * not like the results.
  */
 char *
 make_absolute_path(const char *path)
@@ -713,17 +731,22 @@ CreateLockFile(const char *filename, bool amPostmaster,
 	on_proc_exit(UnlinkLockFile, PointerGetDatum(strdup(filename)));
 }
 
+/*
+ * Create the data directory lockfile.
+ *
+ * When this is called, we must have already switched the working
+ * directory to DataDir, so we can just use a relative path.  This
+ * helps ensure that we are locking the directory we should be.
+ */
 void
-CreateDataDirLockFile(const char *datadir, bool amPostmaster)
+CreateDataDirLockFile(bool amPostmaster)
 {
-	char		lockfile[MAXPGPATH];
-
-	snprintf(lockfile, sizeof(lockfile), "%s/postmaster.pid", datadir);
-	CreateLockFile(lockfile, amPostmaster, true, datadir);
-	/* Save name of lockfile for RecordSharedMemoryInLockFile */
-	strcpy(directoryLockFile, lockfile);
+	CreateLockFile(DIRECTORY_LOCK_FILE, amPostmaster, true, DataDir);
 }
 
+/*
+ * Create a lockfile for the specified Unix socket file.
+ */
 void
 CreateSocketLockFile(const char *socketfile, bool amPostmaster)
 {
@@ -777,7 +800,7 @@ TouchSocketLockFile(void)
 
 /*
  * Append information about a shared memory segment to the data directory
- * lock file (if we have created one).
+ * lock file.
  *
  * This may be called multiple times in the life of a postmaster, if we
  * delete and recreate shmem due to backend crash.	Therefore, be prepared
@@ -793,20 +816,13 @@ RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
 	char	   *ptr;
 	char		buffer[BLCKSZ];
 
-	/*
-	 * Do nothing if we did not create a lockfile (probably because we are
-	 * running standalone).
-	 */
-	if (directoryLockFile[0] == '\0')
-		return;
-
-	fd = open(directoryLockFile, O_RDWR | PG_BINARY, 0);
+	fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0);
 	if (fd < 0)
 	{
 		ereport(LOG,
 				(errcode_for_file_access(),
 				 errmsg("could not open file \"%s\": %m",
-						directoryLockFile)));
+						DIRECTORY_LOCK_FILE)));
 		return;
 	}
 	len = read(fd, buffer, sizeof(buffer) - 100);
@@ -815,7 +831,7 @@ RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
 		ereport(LOG,
 				(errcode_for_file_access(),
 				 errmsg("could not read from file \"%s\": %m",
-						directoryLockFile)));
+						DIRECTORY_LOCK_FILE)));
 		close(fd);
 		return;
 	}
@@ -828,7 +844,7 @@ RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
 	if (ptr == NULL ||
 		(ptr = strchr(ptr + 1, '\n')) == NULL)
 	{
-		elog(LOG, "bogus data in \"%s\"", directoryLockFile);
+		elog(LOG, "bogus data in \"%s\"", DIRECTORY_LOCK_FILE);
 		close(fd);
 		return;
 	}
@@ -855,7 +871,7 @@ RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
 		ereport(LOG,
 				(errcode_for_file_access(),
 				 errmsg("could not write to file \"%s\": %m",
-						directoryLockFile)));
+						DIRECTORY_LOCK_FILE)));
 		close(fd);
 		return;
 	}
@@ -864,7 +880,7 @@ RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2)
 		ereport(LOG,
 				(errcode_for_file_access(),
 				 errmsg("could not write to file \"%s\": %m",
-						directoryLockFile)));
+						DIRECTORY_LOCK_FILE)));
 	}
 }
 

src/backend/utils/init/postinit.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/init/postinit.c,v 1.151 2005/06/28 19:51:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/init/postinit.c,v 1.152 2005/07/04 04:51:50 tgl Exp $
  *
  *
  *-------------------------------------------------------------------------
@@ -338,12 +338,6 @@ InitPostgres(const char *dbname, const char *username)
 
 		ValidatePgVersion(fullpath);
 
-		if (chdir(fullpath) == -1)
-			ereport(FATAL,
-					(errcode_for_file_access(),
-					 errmsg("could not change directory to \"%s\": %m",
-							fullpath)));
-
 		SetDatabasePath(fullpath);
 	}
 

src/backend/utils/misc/guc.c

@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.271 2005/06/28 05:09:02 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.272 2005/07/04 04:51:51 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -74,6 +74,7 @@
 
 #ifdef EXEC_BACKEND
 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
+#define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
 #endif
 
 /* XXX these should appear in other modules' header files */
@@ -2619,7 +2620,9 @@ SelectConfigFiles(const char *userDoption, const char *progname)
 	 * Reflect the final DataDir value back into the data_directory GUC var.
 	 * (If you are wondering why we don't just make them a single variable,
 	 * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
-	 * child backends specially.)
+	 * child backends specially.  XXX is that still true?  Given that we
+	 * now chdir to DataDir, EXEC_BACKEND can read the config file without
+	 * knowing DataDir in advance.)
 	 */
 	SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
 
@@ -4849,6 +4852,7 @@ _ShowOption(struct config_generic * record)
 
 
 #ifdef EXEC_BACKEND
+
 /*
  *	This routine dumps out all non-default GUC options into a binary
  *	file that is read by all exec'ed backends.  The format is:
@@ -4861,42 +4865,23 @@ void
 write_nondefault_variables(GucContext context)
 {
 	int			i;
-	char	   *new_filename,
-			   *filename;
 	int			elevel;
 	FILE	   *fp;
 
 	Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
-	Assert(DataDir);
 
 	elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
 
 	/*
 	 * Open file
 	 */
-	new_filename = guc_malloc(elevel, strlen(DataDir) + strlen(CONFIG_EXEC_PARAMS) +
-							  strlen(".new") + 2);
-	if (new_filename == NULL)
-		return;
-
-	filename = guc_malloc(elevel, strlen(DataDir) + strlen(CONFIG_EXEC_PARAMS) + 2);
-	if (filename == NULL)
-	{
-		free(new_filename);
-		return;
-	}
-
-	sprintf(new_filename, "%s/" CONFIG_EXEC_PARAMS ".new", DataDir);
-	sprintf(filename, "%s/" CONFIG_EXEC_PARAMS, DataDir);
-
-	fp = AllocateFile(new_filename, "w");
+	fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
 	if (!fp)
 	{
-		free(new_filename);
-		free(filename);
 		ereport(elevel,
 				(errcode_for_file_access(),
-				 errmsg("could not write to file \"%s\": %m", CONFIG_EXEC_PARAMS)));
+				 errmsg("could not write to file \"%s\": %m",
+						CONFIG_EXEC_PARAMS_NEW)));
 		return;
 	}
 
@@ -4956,11 +4941,10 @@ write_nondefault_variables(GucContext context)
 
 	if (FreeFile(fp))
 	{
-		free(new_filename);
-		free(filename);
 		ereport(elevel,
 				(errcode_for_file_access(),
-				 errmsg("could not write to file \"%s\": %m", CONFIG_EXEC_PARAMS)));
+				 errmsg("could not write to file \"%s\": %m",
+						CONFIG_EXEC_PARAMS_NEW)));
 		return;
 	}
 
@@ -4968,9 +4952,7 @@ write_nondefault_variables(GucContext context)
 	 * Put new file in place.  This could delay on Win32, but we don't
 	 * hold any exclusive locks.
 	 */
-	rename(new_filename, filename);
-	free(new_filename);
-	free(filename);
+	rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
 }
 
 
@@ -5014,29 +4996,23 @@ read_string_with_null(FILE *fp)
 void
 read_nondefault_variables(void)
 {
-	char	   *filename;
 	FILE	   *fp;
 	char	   *varname,
 			   *varvalue;
 	int			varsource;
 
-	Assert(DataDir);
-
 	/*
 	 * Open file
 	 */
-	filename = guc_malloc(FATAL, strlen(DataDir) + strlen(CONFIG_EXEC_PARAMS) + 2);
-	sprintf(filename, "%s/" CONFIG_EXEC_PARAMS, DataDir);
-
-	fp = AllocateFile(filename, "r");
+	fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
 	if (!fp)
 	{
-		free(filename);
 		/* File not found is fine */
 		if (errno != ENOENT)
 			ereport(FATAL,
 					(errcode_for_file_access(),
-					 errmsg("could not read from file \"%s\": %m", CONFIG_EXEC_PARAMS)));
+					 errmsg("could not read from file \"%s\": %m",
+							CONFIG_EXEC_PARAMS)));
 		return;
 	}
 
@@ -5061,10 +5037,9 @@ read_nondefault_variables(void)
 	}
 
 	FreeFile(fp);
-	free(filename);
-	return;
 }
-#endif
+
+#endif /* EXEC_BACKEND */
 
 
 /*

src/bin/pg_resetxlog/pg_resetxlog.c

@@ -23,7 +23,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.34 2005/06/08 15:50:27 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.35 2005/07/04 04:51:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,9 +50,6 @@ extern int	optind;
 extern char *optarg;
 
 
-char		XLogDir[MAXPGPATH]; /* not static, see xlog_internal.h */
-static char ControlFilePath[MAXPGPATH];
-
 static ControlFileData ControlFile;		/* pg_control values */
 static uint32 newXlogId,
 			newXlogSeg;			/* ID/Segment of new XLOG segment */
@@ -236,8 +233,13 @@ main(int argc, char *argv[])
 #endif
 
 	DataDir = argv[optind];
-	snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
-	snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
+
+	if (chdir(DataDir) < 0)
+	{
+		fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
+				progname, DataDir, strerror(errno));
+		exit(1);
+	}
 
 	/*
 	 * Check for a postmaster lock file --- if there is one, refuse to
@@ -348,7 +350,7 @@ ReadControlFile(void)
 	char	   *buffer;
 	pg_crc32	crc;
 
-	if ((fd = open(ControlFilePath, O_RDONLY)) < 0)
+	if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY)) < 0)
 	{
 		/*
 		 * If pg_control is not there at all, or we can't read it, the
@@ -356,12 +358,12 @@ ReadControlFile(void)
 		 * can do "touch pg_control" to force us to proceed.
 		 */
 		fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
-				progname, ControlFilePath, strerror(errno));
+				progname, XLOG_CONTROL_FILE, strerror(errno));
 		if (errno == ENOENT)
 			fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 							  "  touch %s\n"
 							  "and try again.\n"),
-					ControlFilePath);
+					XLOG_CONTROL_FILE);
 		exit(1);
 	}
 
@@ -372,7 +374,7 @@ ReadControlFile(void)
 	if (len < 0)
 	{
 		fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
-				progname, ControlFilePath, strerror(errno));
+				progname, XLOG_CONTROL_FILE, strerror(errno));
 		exit(1);
 	}
 	close(fd);
@@ -598,9 +600,11 @@ RewriteControlFile(void)
 	memset(buffer, 0, BLCKSZ);
 	memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 
-	unlink(ControlFilePath);
+	unlink(XLOG_CONTROL_FILE);
 
-	fd = open(ControlFilePath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
+	fd = open(XLOG_CONTROL_FILE,
+			  O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
+			  S_IRUSR | S_IWUSR);
 	if (fd < 0)
 	{
 		fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
@@ -639,11 +643,11 @@ KillExistingXLOG(void)
 	struct dirent *xlde;
 	char		path[MAXPGPATH];
 
-	xldir = opendir(XLogDir);
+	xldir = opendir(XLOGDIR);
 	if (xldir == NULL)
 	{
 		fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
-				progname, XLogDir, strerror(errno));
+				progname, XLOGDIR, strerror(errno));
 		exit(1);
 	}
 
@@ -653,7 +657,7 @@ KillExistingXLOG(void)
 		if (strlen(xlde->d_name) == 24 &&
 			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 		{
-			snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
+			snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 			if (unlink(path) < 0)
 			{
 				fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
@@ -676,7 +680,7 @@ KillExistingXLOG(void)
 	if (errno)
 	{
 		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
-				progname, XLogDir, strerror(errno));
+				progname, XLOGDIR, strerror(errno));
 		exit(1);
 	}
 	closedir(xldir);

src/include/access/slru.h

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/slru.h,v 1.11 2004/12/31 22:03:21 pgsql Exp $
+ * $PostgreSQL: pgsql/src/include/access/slru.h,v 1.12 2005/07/04 04:51:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -87,7 +87,7 @@ typedef struct SlruCtlData
 	 * Dir is set during SimpleLruInit and does not change thereafter.
 	 * Since it's always the same, it doesn't need to be in shared memory.
 	 */
-	char		Dir[MAXPGPATH];
+	char		Dir[64];
 } SlruCtlData;
 
 typedef SlruCtlData *SlruCtl;

src/include/access/xlog.h

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/xlog.h,v 1.65 2005/06/08 15:50:28 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/xlog.h,v 1.66 2005/07/04 04:51:52 tgl Exp $
  */
 #ifndef XLOG_H
 #define XLOG_H
@@ -158,7 +158,6 @@ extern void xlog_desc(char *buf, uint8 xl_info, char *rec);
 extern void UpdateControlFile(void);
 extern int	XLOGShmemSize(void);
 extern void XLOGShmemInit(void);
-extern void XLOGPathInit(void);
 extern void BootStrapXLOG(void);
 extern void StartupXLOG(void);
 extern void ShutdownXLOG(int code, Datum arg);

src/include/access/xlog_internal.h

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/xlog_internal.h,v 1.8 2005/06/06 17:01:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/xlog_internal.h,v 1.9 2005/07/04 04:51:52 tgl Exp $
  */
 #ifndef XLOG_INTERNAL_H
 #define XLOG_INTERNAL_H
@@ -185,6 +185,12 @@ typedef XLogLongPageHeaderData *XLogLongPageHeader;
 		((xrecoff) % BLCKSZ >= SizeOfXLogShortPHD && \
 		(BLCKSZ - (xrecoff) % BLCKSZ) >= SizeOfXLogRecord)
 
+/*
+ * The XLog directory and control file (relative to $PGDATA)
+ */
+#define XLOGDIR				"pg_xlog"
+#define XLOG_CONTROL_FILE	"global/pg_control"
+
 /*
  * These macros encapsulate knowledge about the exact layout of XLog file
  * names, timeline history file names, and archive-status file names.
@@ -195,24 +201,22 @@ typedef XLogLongPageHeaderData *XLogLongPageHeader;
 	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X", tli, log, seg)
 
 #define XLogFilePath(path, tli, log, seg)	\
-	snprintf(path, MAXPGPATH, "%s/%08X%08X%08X", XLogDir, tli, log, seg)
+	snprintf(path, MAXPGPATH, XLOGDIR "/%08X%08X%08X", tli, log, seg)
 
 #define TLHistoryFileName(fname, tli)	\
 	snprintf(fname, MAXFNAMELEN, "%08X.history", tli)
 
 #define TLHistoryFilePath(path, tli)	\
-	snprintf(path, MAXPGPATH, "%s/%08X.history", XLogDir, tli)
+	snprintf(path, MAXPGPATH, XLOGDIR "/%08X.history", tli)
 
 #define StatusFilePath(path, xlog, suffix)	\
-	snprintf(path, MAXPGPATH, "%s/archive_status/%s%s", XLogDir, xlog, suffix)
+	snprintf(path, MAXPGPATH, XLOGDIR "/archive_status/%s%s", xlog, suffix)
 
 #define BackupHistoryFileName(fname, tli, log, seg, offset) \
 	snprintf(fname, MAXFNAMELEN, "%08X%08X%08X.%08X.backup", tli, log, seg, offset)
 
 #define BackupHistoryFilePath(path, tli, log, seg, offset)	\
-	snprintf(path, MAXPGPATH, "%s/%08X%08X%08X.%08X.backup", XLogDir, tli, log, seg, offset)
-
-extern char XLogDir[MAXPGPATH];
+	snprintf(path, MAXPGPATH, XLOGDIR "/%08X%08X%08X.%08X.backup", tli, log, seg, offset)
 
 
 /*

src/include/miscadmin.h

@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.176 2005/06/28 05:09:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.177 2005/07/04 04:51:52 tgl Exp $
  *
  * NOTES
  *	  some of the information in this file should be moved to other files.
@@ -238,6 +238,7 @@ extern void InitializeSessionUserIdStandalone(void);
 extern void SetSessionAuthorization(Oid roleid, bool is_superuser);
 
 extern void SetDataDir(const char *dir);
+extern void ChangeToDataDir(void);
 extern char *make_absolute_path(const char *path);
 
 /* in utils/misc/superuser.c */
@@ -309,7 +310,7 @@ extern void SetReindexProcessing(Oid heapOid, Oid indexOid);
 extern void ResetReindexProcessing(void);
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
-extern void CreateDataDirLockFile(const char *datadir, bool amPostmaster);
+extern void CreateDataDirLockFile(bool amPostmaster);
 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
 extern void TouchSocketLockFile(void);
 extern void RecordSharedMemoryInLockFile(unsigned long id1,