From: Kurt Zeilenga <kurt@openldap.org>
Date: Thu, 23 Sep 1999 19:49:20 +0000 (+0000)
Subject: Reimplement LDBM_SYNC/LDBM_NOSYNC code (dbnosync).
X-Git-Tag: UCDATA_2_4~389
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35655c056f2ea487ec5bbf53026bfef59be12bbf;p=thirdparty%2Fopenldap.git

Reimplement LDBM_SYNC/LDBM_NOSYNC code (dbnosync).
Old code applied sync flags to store(), however supported DBMs
require such flags to be specified during open().  The new
code now applies flags in ldbm_cache_open (which calls ldbm_open).
ldbm_cache_close() now calls ldbm_sync().  This will force
a updating of on-disk contents after each LDAP operation.
The old code either failed to sync the on-disk contents until
close or synced on every store.   Per LDBM operation syncing
*should* be safe enough... real data safety requires transactions.
Removed nosync option from BDB2 as it is not compatible with
txn support.
Also added code to disable DBM level locking as slapd is only
process acessing the databases (dbnolocking).
---

diff --git a/doc/man/man5/slapd.conf.5 b/doc/man/man5/slapd.conf.5
index 14b1b5649c..6f92c102ba 100644
--- a/doc/man/man5/slapd.conf.5
+++ b/doc/man/man5/slapd.conf.5
@@ -387,10 +387,13 @@ Specify the size in bytes of the in-memory cache associated
 with each open index file. If not supported by the underlying database 
 method, this option is ignored without comment.  The default is 100000 bytes.
 .TP
-.B dbcachenowsync
-Specify that database writes should not be immediately synchronized
-with in memory changes.  Enabling this option may improve performance
-at the expense of data security.
+.B dbnolocking
+Specify that no database locking should be performed.  
+Enabling this option may improve performance at the expense of data security.
+.B dbnosync
+Specify that on-disk database contents should not be immediately
+synchronized with in memory changes.  Enabling this option may improve
+performance at the expense of data security.
 .TP
 .B directory <directory>
 Specify the directory where the LDBM files containing the database and
diff --git a/include/ldbm.h b/include/ldbm.h
index cf5a75e429..6f5b78affc 100644
--- a/include/ldbm.h
+++ b/include/ldbm.h
@@ -15,11 +15,11 @@
 
 #include <ldap_cdefs.h>
 
-#ifdef LDBM_USE_DBBTREE
+#if defined( LDBM_USE_DBBTREE ) || defined( LDBM_USE_DBHASH )
 
 /*****************************************************************
  *                                                               *
- * use berkeley db btree package                                 *
+ * use berkeley db btree or hash package                         *
  *                                                               *
  *****************************************************************/
 
@@ -51,8 +51,6 @@ typedef DBT	Datum;
 typedef DB	*LDBM;
 
 
-#define DB_TYPE		DB_BTREE
-
 /* for ldbm_open */
 #ifdef HAVE_BERKELEY_DB2
 typedef DBC	LDBMCursor;
@@ -77,77 +75,25 @@ typedef int LDBMCursor;
 
 LDAP_END_DECL
 
-#  define LDBM_FAST	0
-
-#define LDBM_SUFFIX	".dbb"
-#define LDBM_ORDERED	1
+/* for ldbm_open */
+#define LDBM_NOSYNC	0
+#define LDBM_SYNC	0
+#define LDBM_LOCKING	0
+#define LDBM_NOLOCKING	0
 
 /* for ldbm_insert */
 #define LDBM_INSERT	R_NOOVERWRITE
 #define LDBM_REPLACE	0
-#define LDBM_SYNC	0x80000000
-
-#elif defined( LDBM_USE_DBHASH )
-
-/*****************************************************************
- *                                                               *
- * use berkeley db hash package                                  *
- *                                                               *
- *****************************************************************/
-
-#include <sys/types.h>
-#include <limits.h>
-#include <fcntl.h>
-
-#ifdef HAVE_DB_185_H
-#	include <db_185.h>
-#else
-#	ifdef HAVE_DB1_DB_H
-#		include <db1/db.h>
-#	else
-#		include <db.h>
-#	endif
-#	ifdef LDBM_USE_DB2
-#		define R_NOOVERWRITE DB_NOOVERWRITE
-#		define DEFAULT_DB_PAGE_SIZE 1024
-#	endif
-#endif
-
-LDAP_BEGIN_DECL
-
-typedef DBT	Datum;
-#define dsize	size
-#define dptr	data
-
-typedef DB	*LDBM;
 
-#define DB_TYPE		DB_HASH
-
-/* for ldbm_open */
-#ifdef LDBM_USE_DB2
-typedef DBC	LDBMCursor;
-#	define LDBM_READER	DB_RDONLY
-#	define LDBM_WRITER	0x00000      /* hopefully */
-#	define LDBM_WRCREAT	(DB_NOMMAP|DB_CREATE|DB_THREAD)
-#	define LDBM_NEWDB	(DB_TRUNCATE|DB_CREATE|DB_THREAD)
+#ifdef LDBM_USE_DBBTREE
+#	define LDBM_ORDERED	1
+#	define LDBM_SUFFIX	".dbb"
+#	define DB_TYPE		DB_BTREE
 #else
-typedef int LDBMCursor;
-#	define LDBM_READER	O_RDONLY
-#	define LDBM_WRITER	O_RDWR
-#	define LDBM_WRCREAT	(O_RDWR|O_CREAT)
-#	define LDBM_NEWDB	(O_RDWR|O_TRUNC|O_CREAT)
-#	define LDBM_FAST	0
+#	define LDBM_SUFFIX	".dbh"
+#	define DB_TYPE		DB_HASH
 #endif
 
-LDAP_END_DECL
-
-#define LDBM_SUFFIX	".dbh"
-
-/* for ldbm_insert */
-#define LDBM_INSERT	R_NOOVERWRITE
-#define LDBM_REPLACE	0
-#define LDBM_SYNC	0x80000000
-
 #elif defined( HAVE_GDBM )
 
 /*****************************************************************
@@ -173,14 +119,29 @@ LDAP_END_DECL
 #define LDBM_WRITER	GDBM_WRITER
 #define LDBM_WRCREAT	GDBM_WRCREAT
 #define LDBM_NEWDB	GDBM_NEWDB
-#define LDBM_FAST	GDBM_FAST
+
+#ifdef GDBM_FAST
+#define LDBM_NOSYNC	GDBM_FAST
+#else
+#define LDBM_NOSYNC	0
+#endif
+
+#ifdef GDBM_SYNC
+#define LDBM_SYNC	GDBM_SYNC
+#else
+#define LDBM_SYNC	0
+#endif
+
+#define LDBM_LOCKING	0
+#ifdef GDBM_NOLOCK
+#define LDBM_NOLOCKING	GDBM_NOLOCK
+#endif
 
 #define LDBM_SUFFIX	".gdbm"
 
 /* for ldbm_insert */
 #define LDBM_INSERT	GDBM_INSERT
 #define LDBM_REPLACE	GDBM_REPLACE
-#define LDBM_SYNC	0x80000000
 
 #elif defined( HAVE_MDBM )
 
@@ -209,15 +170,17 @@ LDAP_END_DECL
 #define LDBM_WRITER	O_RDWR
 #define LDBM_WRCREAT	(O_RDWR|O_CREAT)
 #define LDBM_NEWDB	(O_RDWR|O_TRUNC|O_CREAT)
-#define LDBM_FAST	0
+
+#define LDBM_SYNC	0
+#define LDBM_NOSYNC	0
+#define LDBM_LOCKING	0
+#define LDBM_NOLOCKING	0
 
 #define LDBM_SUFFIX	".mdbm"
 
 /* for ldbm_insert */
 #define LDBM_INSERT	MDBM_INSERT
 #define LDBM_REPLACE	MDBM_REPLACE
-#define LDBM_SYNC	0x80000000
-
 
 #elif defined( HAVE_NDBM )
 
@@ -246,14 +209,17 @@ LDAP_END_DECL
 #define LDBM_WRITER	O_WRONLY
 #define LDBM_WRCREAT	(O_RDWR|O_CREAT)
 #define LDBM_NEWDB	(O_RDWR|O_TRUNC|O_CREAT)
-#define LDBM_FAST	0
+
+#define LDBM_NOSYNC	0
+#define LDBM_SYNC	0
+#define LDBM_NOLOCK	0
+#define LDBM_SYNC	0
 
 #define LDBM_SUFFIX	".ndbm"
 
 /* for ldbm_insert */
 #define LDBM_INSERT	DBM_INSERT
 #define LDBM_REPLACE	DBM_REPLACE
-#define LDBM_SYNC	0
 
 #endif
 
diff --git a/servers/slapd/back-bdb2/back-bdb2.h b/servers/slapd/back-bdb2/back-bdb2.h
index 4ebc54422c..082052d2ff 100644
--- a/servers/slapd/back-bdb2/back-bdb2.h
+++ b/servers/slapd/back-bdb2/back-bdb2.h
@@ -192,11 +192,9 @@ struct ldbminfo {
 	struct cache		li_cache;
 	Avlnode			*li_attrs;
 	int			li_dbcachesize;
-	int			li_dbcachewsync;
 
 	/*  a list of all files of the database  */
 	BDB2_TXN_HEAD		li_txn_head;
-
 };
 
 
diff --git a/servers/slapd/back-bdb2/config.c b/servers/slapd/back-bdb2/config.c
index 87d739204a..c21d3f5ca1 100644
--- a/servers/slapd/back-bdb2/config.c
+++ b/servers/slapd/back-bdb2/config.c
@@ -163,10 +163,6 @@ bdb2i_back_db_config_internal(
 		if ( li->li_dbcachesize < DEFAULT_DBCACHE_SIZE )
 			li->li_dbcachesize = DEFAULT_DBCACHE_SIZE;
 
-	/* no write sync */
-	} else if ( strcasecmp( argv[0], "dbcachenowsync" ) == 0 ) {
-		li->li_dbcachewsync = 0;
-
 	/* anything else */
 	} else {
 		fprintf( stderr,
diff --git a/servers/slapd/back-bdb2/dn2id.c b/servers/slapd/back-bdb2/dn2id.c
index 1d4599a826..8610a4c067 100644
--- a/servers/slapd/back-bdb2/dn2id.c
+++ b/servers/slapd/back-bdb2/dn2id.c
@@ -43,8 +43,6 @@ bdb2i_dn2id_add(
 	data.dsize = sizeof(ID);
 
 	flags = LDBM_INSERT;
-	if ( li->li_dbcachewsync ) flags |= LDBM_SYNC;
-
 	rc = bdb2i_cache_store( db, key, data, flags );
 
 	free( key.dptr );
diff --git a/servers/slapd/back-bdb2/id2entry.c b/servers/slapd/back-bdb2/id2entry.c
index 1a151fb1d6..9d79590dcc 100644
--- a/servers/slapd/back-bdb2/id2entry.c
+++ b/servers/slapd/back-bdb2/id2entry.c
@@ -45,7 +45,6 @@ bdb2i_id2entry_add( BackendDB *be, Entry *e )
 
 	/* store it */
 	flags = LDBM_REPLACE;
-	if ( li->li_dbcachewsync ) flags |= LDBM_SYNC;
 	rc = bdb2i_cache_store( db, key, data, flags );
 
 	ldap_pvt_thread_mutex_unlock( &entry2str_mutex );
diff --git a/servers/slapd/back-bdb2/idl.c b/servers/slapd/back-bdb2/idl.c
index c062642d8e..bae985a860 100644
--- a/servers/slapd/back-bdb2/idl.c
+++ b/servers/slapd/back-bdb2/idl.c
@@ -214,7 +214,6 @@ idl_store(
 #endif
 
 	flags = LDBM_REPLACE;
-	if( li->li_dbcachewsync ) flags |= LDBM_SYNC;
 	rc = bdb2i_cache_store( db, key, data, flags );
 
 	/* Debug( LDAP_DEBUG_TRACE, "<= idl_store %d\n", rc, 0, 0 ); */
diff --git a/servers/slapd/back-bdb2/init.c b/servers/slapd/back-bdb2/init.c
index 0eb5080460..10ee85f14f 100644
--- a/servers/slapd/back-bdb2/init.c
+++ b/servers/slapd/back-bdb2/init.c
@@ -169,9 +169,6 @@ bdb2i_back_db_init_internal(
 	/* default database cache size */
 	li->li_dbcachesize = DEFAULT_DBCACHE_SIZE;
 
-	/* default cache mode is sync on write */
-	li->li_dbcachewsync = 1;
-
 	/* default file creation mode */
 	li->li_mode = DEFAULT_MODE;
 
diff --git a/servers/slapd/back-bdb2/tools.c b/servers/slapd/back-bdb2/tools.c
index 662381dfb0..d2ab6a70f6 100644
--- a/servers/slapd/back-bdb2/tools.c
+++ b/servers/slapd/back-bdb2/tools.c
@@ -42,8 +42,6 @@ int bdb2_tool_entry_open(
 		flags = LDBM_READER;
 	}
 
-	li->li_dbcachewsync = 0;
-
 	if ( (id2entry = bdb2i_cache_open( be, "id2entry", BDB2_SUFFIX, flags ))
 	    == NULL ) {
 		Debug( LDAP_DEBUG_ANY, "Could not open/create id2entry" BDB2_SUFFIX "\n",
@@ -63,7 +61,6 @@ int bdb2_tool_entry_close(
 	assert( id2entry != NULL );
 
 	bdb2i_cache_close( be, id2entry );
-	li->li_dbcachewsync = 1;
 	id2entry = NULL;
 
 	return 0;
diff --git a/servers/slapd/back-bdb2/txn.c b/servers/slapd/back-bdb2/txn.c
index 2a711385d1..d4ddc38436 100644
--- a/servers/slapd/back-bdb2/txn.c
+++ b/servers/slapd/back-bdb2/txn.c
@@ -481,8 +481,6 @@ bdb2i_put_nextid( BackendDB *be, ID id )
 	data.size = sizeof( buf );
 
 	flags = LDBM_REPLACE;
-	if ( li->li_dbcachewsync ) flags |= LDBM_SYNC;
-
 	if (( rc = bdb2i_db_store( head->nextidFile, key, data, flags )) != 0 ) {
 		Debug( LDAP_DEBUG_ANY, "next_id_write(%ld): store failed (%d)\n",
 			id, rc, 0 );
@@ -522,7 +520,7 @@ bdb2i_db_store( LDBM ldbm, Datum key, Datum data, int flags )
 {
 	int     rc;
 
-	rc = (*ldbm->put)( ldbm, txnid, &key, &data, flags & ~LDBM_SYNC );
+	rc = (*ldbm->put)( ldbm, txnid, &key, &data, flags );
 	rc = (-1 ) * rc;
 
 	if ( txnid != NULL ) {
diff --git a/servers/slapd/back-ldbm/back-ldbm.h b/servers/slapd/back-ldbm/back-ldbm.h
index cf381da96f..1c1154ec37 100644
--- a/servers/slapd/back-ldbm/back-ldbm.h
+++ b/servers/slapd/back-ldbm/back-ldbm.h
@@ -138,8 +138,9 @@ struct ldbminfo {
 	char			*li_directory;
 	Cache		li_cache;
 	Avlnode			*li_attrs;
+	int			li_dblocking;	/* lock databases */
+	int			li_dbwritesync;	/* write sync */
 	int			li_dbcachesize;
-	int			li_dbcachewsync;
 	DBCache		li_dbcache[MAXDBCACHE];
 	ldap_pvt_thread_mutex_t		li_dbcache_mutex;
 	ldap_pvt_thread_cond_t		li_dbcache_cv;
diff --git a/servers/slapd/back-ldbm/config.c b/servers/slapd/back-ldbm/config.c
index ef06a4fcc7..daad7e9b7e 100644
--- a/servers/slapd/back-ldbm/config.c
+++ b/servers/slapd/back-ldbm/config.c
@@ -89,9 +89,15 @@ ldbm_back_db_config(
 		}
 		li->li_dbcachesize = atoi( argv[1] );
 
-	/* no write sync */
-	} else if ( strcasecmp( argv[0], "dbcachenowsync" ) == 0 ) {
-		li->li_dbcachewsync = 0;
+	/* no locking (not safe) */
+	} else if ( strcasecmp( argv[0], "dbnolocking" ) == 0 ) {
+		li->li_dblocking = 0;
+
+	/* no write sync (not safe) */
+	} else if ( ( strcasecmp( argv[0], "dbnosync" ) == 0 )
+		|| ( strcasecmp( argv[0], "dbcachenowsync" ) == 0 ) )
+	{
+		li->li_dbwritesync = 0;
 
 	/* anything else */
 	} else {
diff --git a/servers/slapd/back-ldbm/dbcache.c b/servers/slapd/back-ldbm/dbcache.c
index eecf2c954b..614a643bbe 100644
--- a/servers/slapd/back-ldbm/dbcache.c
+++ b/servers/slapd/back-ldbm/dbcache.c
@@ -42,6 +42,18 @@ ldbm_cache_open(
 	sprintf( buf, "%s" LDAP_DIRSEP "%s%s",
 		li->li_directory, name, suffix );
 
+	if( li->li_dblocking ) {
+		flags |= LDBM_LOCKING;
+	} else {
+		flags |= LDBM_NOLOCKING;
+	}
+	
+	if( li->li_dbwritesync ) {
+		flags |= LDBM_SYNC;
+	} else {
+		flags |= LDBM_NOSYNC;
+	}
+	
 	Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
 	    flags, li->li_mode );
 
@@ -135,6 +147,10 @@ ldbm_cache_close( Backend *be, DBCache *db )
 {
 	struct ldbminfo	*li = (struct ldbminfo *) be->be_private;
 
+	if( li->li_dbwritesync ) {
+		ldbm_sync( db->dbc_db );
+	}
+
 	ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
 	if ( --db->dbc_refcnt == 0 ) {
 		ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
diff --git a/servers/slapd/back-ldbm/dn2id.c b/servers/slapd/back-ldbm/dn2id.c
index afa1c27de6..567ff24d0c 100644
--- a/servers/slapd/back-ldbm/dn2id.c
+++ b/servers/slapd/back-ldbm/dn2id.c
@@ -48,8 +48,6 @@ dn2id_add(
 	data.dsize = sizeof(ID);
 
 	flags = LDBM_INSERT;
-	if ( li->li_dbcachewsync ) flags |= LDBM_SYNC;
-
 	rc = ldbm_cache_store( db, key, data, flags );
 
 	free( key.dptr );
diff --git a/servers/slapd/back-ldbm/id2entry.c b/servers/slapd/back-ldbm/id2entry.c
index 53f52d85a5..f042e02044 100644
--- a/servers/slapd/back-ldbm/id2entry.c
+++ b/servers/slapd/back-ldbm/id2entry.c
@@ -49,7 +49,6 @@ id2entry_add( Backend *be, Entry *e )
 
 	/* store it */
 	flags = LDBM_REPLACE;
-	if ( li->li_dbcachewsync ) flags |= LDBM_SYNC;
 	rc = ldbm_cache_store( db, key, data, flags );
 
 	ldap_pvt_thread_mutex_unlock( &entry2str_mutex );
diff --git a/servers/slapd/back-ldbm/idl.c b/servers/slapd/back-ldbm/idl.c
index f528fa8665..22093a78e6 100644
--- a/servers/slapd/back-ldbm/idl.c
+++ b/servers/slapd/back-ldbm/idl.c
@@ -217,7 +217,6 @@ idl_store(
 #endif
 
 	flags = LDBM_REPLACE;
-	if( li->li_dbcachewsync ) flags |= LDBM_SYNC;
 	rc = ldbm_cache_store( db, key, data, flags );
 
 	/* Debug( LDAP_DEBUG_TRACE, "<= idl_store %d\n", rc, 0, 0 ); */
diff --git a/servers/slapd/back-ldbm/init.c b/servers/slapd/back-ldbm/init.c
index d7b6345e9f..110647f7a3 100644
--- a/servers/slapd/back-ldbm/init.c
+++ b/servers/slapd/back-ldbm/init.c
@@ -130,8 +130,11 @@ ldbm_back_db_init(
 	/* default database cache size */
 	li->li_dbcachesize = DEFAULT_DBCACHE_SIZE;
 
-	/* default cache mode is sync on write */
-	li->li_dbcachewsync = 1;
+	/* default db mode is with locking */ 
+	li->li_dblocking = 1;
+
+	/* default db mode is with write synchronization */ 
+	li->li_dbwritesync = 1;
 
 	/* default file creation mode */
 	li->li_mode = DEFAULT_MODE;
diff --git a/servers/slapd/back-ldbm/nextid.c b/servers/slapd/back-ldbm/nextid.c
index ebe6f38971..19cca1c399 100644
--- a/servers/slapd/back-ldbm/nextid.c
+++ b/servers/slapd/back-ldbm/nextid.c
@@ -77,8 +77,6 @@ next_id_write( Backend *be, ID id )
 	data.dsize = sizeof(ID);
 
 	flags = LDBM_REPLACE;
-	if( li->li_dbcachewsync ) flags |= LDBM_SYNC;
-
 	if ( ldbm_cache_store( db, key, data, flags ) != 0 ) {
 		id = NOID;
 	}
diff --git a/servers/slapd/back-ldbm/tools.c b/servers/slapd/back-ldbm/tools.c
index 840449e473..c36d82cf23 100644
--- a/servers/slapd/back-ldbm/tools.c
+++ b/servers/slapd/back-ldbm/tools.c
@@ -42,7 +42,7 @@ int ldbm_tool_entry_open(
 		flags = LDBM_READER;
 	}
 
-	li->li_dbcachewsync = 0;
+	li->li_dbwritesync = 0;
 
 	if ( (id2entry = ldbm_cache_open( be, "id2entry", LDBM_SUFFIX, flags ))
 	    == NULL ) {
@@ -63,7 +63,7 @@ int ldbm_tool_entry_close(
 	assert( id2entry != NULL );
 
 	ldbm_cache_close( be, id2entry );
-	li->li_dbcachewsync = 1;
+	li->li_dbwritesync = 1;
 	id2entry = NULL;
 
 	return 0;
diff --git a/tests/data/slapd-bdb2-repl-slave.conf b/tests/data/slapd-bdb2-repl-slave.conf
index 7e2ad2c612..a0554a2016 100644
--- a/tests/data/slapd-bdb2-repl-slave.conf
+++ b/tests/data/slapd-bdb2-repl-slave.conf
@@ -29,4 +29,3 @@ index		cn,sn,uid	pres,eq,approx
 index		default		none
 # index		default		pres,eq,approx
 lastmod		on
-dbcachenowsync
diff --git a/tests/data/slapd-master.conf b/tests/data/slapd-master.conf
index d1c2387e20..e9facfe8dc 100644
--- a/tests/data/slapd-master.conf
+++ b/tests/data/slapd-master.conf
@@ -20,4 +20,5 @@ rootpw		secret
 index		cn,sn,uid	pres,eq,approx
 index		default		none
 lastmod		on
-dbcachenowsync
+dbnosync
+dbnolocking