Index: doc/src/sgml/maintenance.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v
retrieving revision 1.41
diff -c -r1.41 maintenance.sgml
*** doc/src/sgml/maintenance.sgml	20 Feb 2005 02:21:26 -0000	1.41
--- doc/src/sgml/maintenance.sgml	26 Apr 2005 22:02:22 -0000
***************
*** 474,479 ****
--- 474,496 ----
    </para>
   </sect1>
  
+  <sect1 id="cleanup-after-crash">
+   <title>Cleanup after crash</title>
+ 
+   <indexterm zone="cleanup-after-crash">
+    <primary>stale file</primary>
+   </indexterm>
+ 
+   <para>
+    <productname>PostgreSQL</productname> recovers automatically after crash
+    using the write-ahead log (see <xref linkend="wal">) and no manual 
+    operations are normally needed. However, if there was a transaction running 
+    when the crash occured that created or dropped a relation, the 
+    transaction might have left a stale file in the data directory. If this 
+    happens, you will get a notice in the log file stating which files can be 
+    deleted.
+   </para>
+  </sect1>
  
   <sect1 id="logfile-maintenance">
    <title>Log File Maintenance</title>
Index: src/backend/access/transam/xlog.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.188
diff -c -r1.188 xlog.c
*** src/backend/access/transam/xlog.c	23 Apr 2005 18:49:54 -0000	1.188
--- src/backend/access/transam/xlog.c	26 Apr 2005 22:02:22 -0000
***************
*** 42,47 ****
--- 42,48 ----
  #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/relcache.h"
+ #include "utils/cleanup.h"
  
  
  /*
***************
*** 4520,4525 ****
--- 4521,4528 ----
  
  		CreateCheckPoint(true, true);
  
+ 		CleanupStaleRelFiles();
+ 
  		/*
  		 * Close down recovery environment
  		 */
Index: src/backend/catalog/catalog.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/catalog/catalog.c,v
retrieving revision 1.59
diff -c -r1.59 catalog.c
*** src/backend/catalog/catalog.c	14 Apr 2005 20:03:23 -0000	1.59
--- src/backend/catalog/catalog.c	26 Apr 2005 22:02:22 -0000
***************
*** 106,111 ****
--- 106,144 ----
  	return path;
  }
  
+ /*
+  * GetTablespacePath	- construct path to a tablespace symbolic link
+  *
+  * Result is a palloc'd string.
+  *
+  * XXX this must agree with relpath and GetDatabasePath!
+  */
+ char *
+ GetTablespacePath(Oid spcNode)
+ {
+ 	int			pathlen;
+ 	char	   *path;
+ 
+ 	Assert(spcNode != GLOBALTABLESPACE_OID);
+ 
+ 	if (spcNode == DEFAULTTABLESPACE_OID)
+ 	{
+ 		/* The default tablespace is {datadir}/base */
+ 		pathlen = strlen(DataDir) + 5 + 1;
+ 		path = (char *) palloc(pathlen);
+ 		snprintf(path, pathlen, "%s/base",
+ 				 DataDir);
+ 	}
+ 	else
+ 	{
+ 		/* All other tablespaces have symlinks in pg_tblspc */
+ 		pathlen = strlen(DataDir) + 11 + OIDCHARS + 1;
+ 		path = (char *) palloc(pathlen);
+ 		snprintf(path, pathlen, "%s/pg_tblspc/%u",
+ 				 DataDir, spcNode);
+ 	}
+ 	return path;
+ }
  
  /*
   * IsSystemRelation
Index: src/backend/commands/tablespace.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/commands/tablespace.c,v
retrieving revision 1.17
diff -c -r1.17 tablespace.c
*** src/backend/commands/tablespace.c	14 Apr 2005 20:03:24 -0000	1.17
--- src/backend/commands/tablespace.c	26 Apr 2005 22:02:23 -0000
***************
*** 341,348 ****
  	/*
  	 * All seems well, create the symlink
  	 */
! 	linkloc = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
! 	sprintf(linkloc, "%s/pg_tblspc/%u", DataDir, tablespaceoid);
  
  	if (symlink(location, linkloc) < 0)
  		ereport(ERROR,
--- 341,347 ----
  	/*
  	 * All seems well, create the symlink
  	 */
! 	linkloc = GetTablespacePath(tablespaceoid);
  
  	if (symlink(location, linkloc) < 0)
  		ereport(ERROR,
***************
*** 495,502 ****
  	char	   *subfile;
  	struct stat st;
  
! 	location = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
! 	sprintf(location, "%s/pg_tblspc/%u", DataDir, tablespaceoid);
  
  	/*
  	 * Check if the tablespace still contains any files.  We try to rmdir
--- 494,500 ----
  	char	   *subfile;
  	struct stat st;
  
! 	location = GetTablespacePath(tablespaceoid);
  
  	/*
  	 * Check if the tablespace still contains any files.  We try to rmdir
***************
*** 1036,1043 ****
  		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);
  
  		if (symlink(location, linkloc) < 0)
  		{
--- 1034,1040 ----
  		set_short_version(location);
  
  		/* Create the symlink if not already present */
! 		linkloc = GetTablespacePath(xlrec->ts_id);
  
  		if (symlink(location, linkloc) < 0)
  		{
Index: src/backend/utils/adt/misc.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/adt/misc.c,v
retrieving revision 1.40
diff -c -r1.40 misc.c
*** src/backend/utils/adt/misc.c	31 Dec 2004 22:01:22 -0000	1.40
--- src/backend/utils/adt/misc.c	26 Apr 2005 22:02:23 -0000
***************
*** 26,31 ****
--- 26,32 ----
  #include "funcapi.h"
  #include "catalog/pg_type.h"
  #include "catalog/pg_tablespace.h"
+ #include "catalog/catalog.h"
  
  #define atooid(x)  ((Oid) strtoul((x), NULL, 10))
  
***************
*** 144,154 ****
  
  		fctx = palloc(sizeof(ts_db_fctx));
  
- 		/*
- 		 * size = path length + tablespace dirname length + 2 dir sep
- 		 * chars + oid + terminator
- 		 */
- 		fctx->location = (char *) palloc(strlen(DataDir) + 11 + 10 + 1);
  		if (tablespaceOid == GLOBALTABLESPACE_OID)
  		{
  			fctx->dirdesc = NULL;
--- 145,150 ----
***************
*** 157,168 ****
  		}
  		else
  		{
! 			if (tablespaceOid == DEFAULTTABLESPACE_OID)
! 				sprintf(fctx->location, "%s/base", DataDir);
! 			else
! 				sprintf(fctx->location, "%s/pg_tblspc/%u", DataDir,
! 						tablespaceOid);
! 
  			fctx->dirdesc = AllocateDir(fctx->location);
  
  			if (!fctx->dirdesc)
--- 153,159 ----
  		}
  		else
  		{
! 			fctx->location = GetTablespacePath(tablespaceOid);
  			fctx->dirdesc = AllocateDir(fctx->location);
  
  			if (!fctx->dirdesc)
Index: src/backend/utils/init/Makefile
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/init/Makefile,v
retrieving revision 1.18
diff -c -r1.18 Makefile
*** src/backend/utils/init/Makefile	20 Feb 2005 02:22:00 -0000	1.18
--- src/backend/utils/init/Makefile	26 Apr 2005 22:02:23 -0000
***************
*** 12,18 ****
  top_builddir = ../../../..
  include $(top_builddir)/src/Makefile.global
  
! OBJS = flatfiles.o globals.o miscinit.o postinit.o
  
  all: SUBSYS.o
  
--- 12,18 ----
  top_builddir = ../../../..
  include $(top_builddir)/src/Makefile.global
  
! OBJS = flatfiles.o globals.o miscinit.o postinit.o cleanup.o
  
  all: SUBSYS.o
  
Index: src/backend/utils/init/cleanup.c
===================================================================
RCS file: src/backend/utils/init/cleanup.c
diff -N src/backend/utils/init/cleanup.c
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- src/backend/utils/init/cleanup.c	26 Apr 2005 22:02:23 -0000
***************
*** 0 ****
--- 1,209 ----
+ /*-------------------------------------------------------------------------
+  *
+  * cleanup.c
+  *	  support to clean up stale relation files on crash recovery
+  *
+  * If a backend crashes while in a transaction that has created or
+  * deleted a relfilenode, a stale file can be left over in the data
+  * directory. This file contains routines to clean up those stale
+  * files on recovery.
+  *
+  * $PostgreSQL$
+  *
+  *-------------------------------------------------------------------------
+  */
+ #include "postgres.h"
+ 
+ #include "storage/fd.h"
+ 
+ #include "utils/cleanup.h"
+ #include "miscadmin.h"
+ #include "catalog/pg_tablespace.h"
+ #include "catalog/catalog.h"
+ #include "access/skey.h"
+ #include "utils/fmgroids.h"
+ #include "access/relscan.h"
+ #include "access/heapam.h"
+ #include "utils/resowner.h"
+ 
+ static void CleanupStaleRelFilesFrom(Oid tablespaceoid, Oid dboid);
+ static void CleanupStaleRelFilesFromTablespace(Oid tablespaceoid);
+ 
+ /* Like AllocateDir, but ereports on failure */
+ static DIR *
+ AllocateDirChecked(char *path)
+ {
+ 	DIR *dirdesc = AllocateDir(path);
+ 	if (dirdesc == NULL)
+ 		ereport(ERROR,
+ 				(errcode_for_file_access(),
+ 				 errmsg("could not open directory \"%s\": %m",
+ 						path)));
+ 	return dirdesc;
+ }
+ 
+ /*
+  * Scan through all tablespaces for relations left over
+  * by aborted transactions.
+  *
+  * For example, if a transaction issues
+  * BEGIN; CREATE TABLE foobar ();
+  * and then the backend crashes, the file is left in the
+  * tablespace until CleanupStaleRelFiles deletes it.
+  */
+ void
+ CleanupStaleRelFiles(void)
+ {
+ 	DIR                *dirdesc;
+ 	struct dirent *de;
+ 	char       *path;
+ 	int pathlen;
+ 
+ 	pathlen = strlen(DataDir) + 11 + 1;
+ 	path = (char *) palloc(pathlen);
+ 	snprintf(path, pathlen, "%s/pg_tblspc/", DataDir);
+ 	dirdesc = AllocateDirChecked(path);
+ 	while ((de = readdir(dirdesc)) != NULL)
+ 	{
+ 		char *invalid;
+ 		Oid tablespaceoid;
+ 
+ 		/* Check that the directory name looks like valid tablespace link.	*/
+ 		tablespaceoid = (Oid) strtol(de->d_name, &invalid, 10);
+ 		if(invalid[0] == '\0')
+ 			CleanupStaleRelFilesFromTablespace(tablespaceoid);
+ 	}
+ 	pfree(path);
+ 
+ 	CleanupStaleRelFilesFromTablespace(DEFAULTTABLESPACE_OID);
+ }
+ 
+ /* Scan a specific tablespace for stale relations */
+ static void
+ CleanupStaleRelFilesFromTablespace(Oid tablespaceoid)
+ {
+ 	DIR                *dirdesc;
+ 	struct dirent *de;
+ 	char       *path;
+ 
+ 	path = GetTablespacePath(tablespaceoid);
+ 
+ 	dirdesc = AllocateDirChecked(path);
+ 	while ((de = readdir(dirdesc)) != NULL)
+ 	{
+ 		char *invalid;
+ 		Oid dboid;
+ 
+ 		dboid = (Oid) strtol(de->d_name, &invalid, 10);
+ 		if(invalid[0] == '\0')
+ 			CleanupStaleRelFilesFrom(tablespaceoid, dboid);
+ 	}
+ 	pfree(path);
+ }
+ 
+ /* Scan a specific database in a specific tablespace for stale relations.
+  *
+  * First, pg_class for the database is opened, and the relfilenodes of all
+  * relations mentioned there are stored in a hash table.
+  *
+  * Then the directory is scanned. Every file in the directory that's not
+  * found in pg_class (the hash table) is logged.
+  */
+ static void
+ CleanupStaleRelFilesFrom(Oid tablespaceoid, Oid dboid)
+ {
+ 	DIR *dirdesc;
+ 	struct dirent *de;
+ 	HASHCTL hashctl;
+ 	HTAB *relfilenodeHash;
+ 	MemoryContext mcxt;
+ 	RelFileNode rnode;
+ 	char *path;
+ 
+ 	/* We create a private memory context so that we can easily deallocate
+ 	 * the hash table and its contents
+ 	 */
+ 	mcxt = AllocSetContextCreate(TopMemoryContext, "CleanupStaleRelFiles",
+ 								 ALLOCSET_DEFAULT_MINSIZE,
+ 								 ALLOCSET_DEFAULT_INITSIZE,
+ 								 ALLOCSET_DEFAULT_MAXSIZE);
+ 
+ 	hashctl.hash = tag_hash;
+ 	/* The entry contents is not used for anything, we just check
+ 	 * if an oid is in the hash table or not. */
+ 	hashctl.keysize = sizeof(Oid);
+ 	hashctl.entrysize = 1;
+ 	hashctl.hcxt = mcxt;
+ 	relfilenodeHash = hash_create("relfilenodeHash", 100, &hashctl,
+ 								  HASH_FUNCTION
+ 								  | HASH_ELEM | HASH_CONTEXT);
+ 
+ 	/* Read all relfilenodes from pg_class into the hash table */
+ 	{
+ 		ResourceOwner owner;
+ 		ResourceOwner oldowner;
+ 		Relation        rel;
+ 		HeapScanDesc scan;
+ 		HeapTuple tuple;
+ 
+ 		/* Need a resowner to keep the heapam and buffer code happy */
+ 		owner = ResourceOwnerCreate(NULL, "CleanupStaleRelFiles");
+ 		oldowner = CurrentResourceOwner;
+ 		CurrentResourceOwner = owner;
+ 
+ 		rnode.spcNode = tablespaceoid;
+ 		rnode.dbNode = dboid;
+ 		rnode.relNode = RelationRelationId;
+ 		rel = XLogOpenRelation(true, 0 , rnode);
+ 
+ 		scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
+ 		while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ 		{
+ 			Form_pg_class classform = (Form_pg_class) GETSTRUCT(tuple);
+ 
+ 			hash_search(relfilenodeHash, &classform->relfilenode,
+ 						HASH_ENTER, NULL);
+ 		}
+ 		heap_endscan(scan);
+ 
+ 		XLogCloseRelation(rnode);
+ 		CurrentResourceOwner = oldowner;
+ 		ResourceOwnerDelete(owner);
+ 	}
+ 
+ 	/* Scan the directory */
+ 	path = GetDatabasePath(dboid, tablespaceoid);
+ 
+ 	dirdesc = AllocateDirChecked(path);
+ 	while ((de = readdir(dirdesc)) != NULL)
+ 	{
+ 		char *invalid;
+ 		Oid relfilenode;
+ 
+ 		relfilenode = strtol(de->d_name, &invalid, 10);
+ 		if(invalid[0] == '\0')
+ 		{
+ 			/* Filename was a valid number, check if pg_class knows
+ 			   about it */
+ 			if(hash_search(relfilenodeHash, &relfilenode,
+ 						   HASH_FIND, NULL) == NULL)
+ 			{
+ 				char *filepath;
+ 				rnode.spcNode = tablespaceoid;
+ 				rnode.dbNode = dboid;
+ 				rnode.relNode = relfilenode;
+ 				
+ 				filepath = relpath(rnode);
+ 
+ 				ereport(NOTICE,
+ 						(errcode_for_file_access(),
+ 						 errmsg("The relation file \"%s\" is stale and can be safely deleted",
+ 								filepath)));
+ 				pfree(filepath);
+ 			}
+ 		}
+ 	}
+ 	pfree(path);
+ 	hash_destroy(relfilenodeHash);
+ 	MemoryContextDelete(mcxt);
+ }
Index: src/include/catalog/catalog.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/catalog/catalog.h,v
retrieving revision 1.30
diff -c -r1.30 catalog.h
*** src/include/catalog/catalog.h	31 Dec 2004 22:03:24 -0000	1.30
--- src/include/catalog/catalog.h	26 Apr 2005 22:02:23 -0000
***************
*** 19,24 ****
--- 19,25 ----
  
  extern char *relpath(RelFileNode rnode);
  extern char *GetDatabasePath(Oid dbNode, Oid spcNode);
+ extern char *GetTablespacePath(Oid spcNode);
  
  extern bool IsSystemRelation(Relation relation);
  extern bool IsToastRelation(Relation relation);