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.

1 files changed, 14 insertions, 22 deletions

diff --git a/src/backend/storage/freespace/freespace.c b/src/backend/storage/freespace/freespace.c
index 27e9952b3ff..355282db1a4 100644
--- a/src/backend/storage/freespace/freespace.c
+++ b/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);
 }