From 0076b40c329936cf8fc788ca109d1d39e5422c5e Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Thu, 24 Mar 2005 05:13:31 +0000
Subject: [PATCH] Convert backendInfo/backendDB to STAILQs

---
 servers/slapd/abandon.c               |   5 +-
 servers/slapd/acl.c                   |   4 +-
 servers/slapd/back-monitor/backend.c  |  14 +-
 servers/slapd/back-monitor/database.c |  18 ++-
 servers/slapd/back-monitor/overlay.c  |   6 +-
 servers/slapd/backend.c               | 222 +++++++++++---------------
 servers/slapd/backover.c              |   6 +-
 servers/slapd/bconfig.c               |  13 +-
 servers/slapd/cancel.c                |   3 +-
 servers/slapd/config.h                |   6 +
 servers/slapd/overlays/glue.c         |  21 +--
 servers/slapd/root_dse.c              |  27 ++--
 servers/slapd/slap.h                  |  11 +-
 servers/slapd/slapcommon.c            |  22 ++-
 14 files changed, 177 insertions(+), 201 deletions(-)

diff --git a/servers/slapd/abandon.c b/servers/slapd/abandon.c
index efc3ba7c8e..95df80c2a5 100644
--- a/servers/slapd/abandon.c
+++ b/servers/slapd/abandon.c
@@ -108,10 +108,7 @@ do_abandon( Operation *op, SlapReply *rs )
 int
 fe_op_abandon( Operation *op, SlapReply *rs )
 {
-	int i;
-
-	for ( i = 0; i < nbackends; i++ ) {
-		op->o_bd = &backends[i];
+	LDAP_STAILQ_FOREACH( op->o_bd, &backendDB, be_next ) {
 		if ( op->o_bd->be_abandon ) {
 			(void)op->o_bd->be_abandon( op, rs );
 		}
diff --git a/servers/slapd/acl.c b/servers/slapd/acl.c
index fdb2b9156f..2c5551cc3f 100644
--- a/servers/slapd/acl.c
+++ b/servers/slapd/acl.c
@@ -223,7 +223,7 @@ access_allowed_mask(
 
 	be = op->o_bd;
 	if ( be == NULL ) {
-		be = &backends[0];
+		be = LDAP_STAILQ_FIRST(&backendDB);
 		be_null = 1;
 #ifdef LDAP_DEVEL
 		/*
@@ -1725,7 +1725,7 @@ acl_check_modlist(
 
 	be = op->o_bd;
 	if ( be == NULL ) {
-		be = &backends[0];
+		be = LDAP_STAILQ_FIRST(&backendDB);
 		be_null = 1;
 		op->o_bd = be;
 	}
diff --git a/servers/slapd/back-monitor/backend.c b/servers/slapd/back-monitor/backend.c
index d215821791..b9e6084358 100644
--- a/servers/slapd/back-monitor/backend.c
+++ b/servers/slapd/back-monitor/backend.c
@@ -42,6 +42,7 @@ monitor_subsys_backend_init(
 	int			i;
 	monitor_entry_t		*mp;
 	monitor_subsys_t	*ms_database;
+	BackendInfo			*bi;
 
 	mi = ( monitor_info_t * )be->be_private;
 
@@ -69,14 +70,15 @@ monitor_subsys_backend_init(
 	mp->mp_children = NULL;
 	ep = &mp->mp_children;
 
-	for ( i = 0; i < nBackendInfo; i++ ) {
+	i = -1;
+	LDAP_STAILQ_FOREACH( bi, &backendInfo, bi_next ) {
 		char 		buf[ BACKMONITOR_BUFSIZE ];
-		BackendInfo 	*bi;
+		BackendDB		*be;
 		struct berval 	bv;
 		int		j;
 		Entry		*e;
 
-		bi = &backendInfo[ i ];
+		i++;
 
 		snprintf( buf, sizeof( buf ),
 				"dn: cn=Backend %d,%s\n"
@@ -124,11 +126,13 @@ monitor_subsys_backend_init(
 			}
 		}
 
-		for ( j = 0; j < nBackendDB; j++ ) {
-			BackendDB	*be = &backendDB[ j ];
+		j = -1;
+		LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
 			char		buf[ SLAP_LDAPDN_MAXLEN ];
 			struct berval	dn;
 			
+			j++;
+
 			if ( be->bd_info != bi ) {
 				continue;
 			}
diff --git a/servers/slapd/back-monitor/database.c b/servers/slapd/back-monitor/database.c
index 5acedec8ca..1deed07e7d 100644
--- a/servers/slapd/back-monitor/database.c
+++ b/servers/slapd/back-monitor/database.c
@@ -166,14 +166,15 @@ monitor_subsys_database_init(
 	mp->mp_children = NULL;
 	ep = &mp->mp_children;
 
-	for ( i = 0; i < nBackendDB; i++ ) {
+	i = -1;
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
 		char		buf[ BACKMONITOR_BUFSIZE ];
 		int		j;
 		slap_overinfo	*oi = NULL;
-		BackendInfo	*bi;
+		BackendInfo	*bi, *bi2;
 		Entry		*e;
 
-		be = &backendDB[ i ];
+		i++;
 
 		bi = be->bd_info;
 
@@ -356,8 +357,10 @@ monitor_subsys_database_init(
 		}
 #endif /* defined(SLAPD_LDAP) */
 
-		for ( j = 0; j < nBackendInfo; j++ ) {
-			if ( backendInfo[ j ].bi_type == bi->bi_type ) {
+		j = -1;
+		LDAP_STAILQ_FOREACH( bi2, &backendInfo, bi_next ) {
+			j++;
+			if ( bi2->bi_type == bi->bi_type ) {
 				struct berval 		bv;
 
 				snprintf( buf, sizeof( buf ), 
@@ -550,8 +553,11 @@ monitor_subsys_database_modify(
 	if ( n < 0 || n >= nBackendDB )
 		return LDAP_NO_SUCH_OBJECT;
 
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( n == 0 ) break;
+		n--;
+	}
 	/* do not allow some changes on back-monitor (needs work)... */
-	be = &backendDB[ n ];
 	if ( SLAP_MONITOR( be ) )
 		return LDAP_UNWILLING_TO_PERFORM;
 		
diff --git a/servers/slapd/back-monitor/overlay.c b/servers/slapd/back-monitor/overlay.c
index b90fc8a2b0..c68d5152cd 100644
--- a/servers/slapd/back-monitor/overlay.c
+++ b/servers/slapd/back-monitor/overlay.c
@@ -73,6 +73,7 @@ monitor_subsys_overlay_init(
 		struct berval 	bv;
 		int		j;
 		Entry		*e;
+		BackendDB	*be;
 
 		snprintf( buf, sizeof( buf ),
 				"dn: cn=Overlay %d,%s\n"
@@ -110,11 +111,12 @@ monitor_subsys_overlay_init(
 		attr_merge_normalize_one( e_overlay, mi->mi_ad_monitoredInfo,
 				&bv, NULL );
 
-		for ( j = 0; j < nBackendDB; j++ ) {
-			BackendDB	*be = &backendDB[ j ];
+		j = -1;
+		LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
 			char		buf[ SLAP_LDAPDN_MAXLEN ];
 			struct berval	dn;
 
+			j++;
 			if ( !overlay_is_inst( be, on->on_bi.bi_type ) ) {
 				continue;
 			}
diff --git a/servers/slapd/backend.c b/servers/slapd/backend.c
index 1a0277f25c..ea42a39d0a 100644
--- a/servers/slapd/backend.c
+++ b/servers/slapd/backend.c
@@ -57,10 +57,10 @@ static void call_group_postop_plugins( Operation *op );
  */
 
 int			nBackendInfo = 0;
-BackendInfo		*backendInfo = NULL;
+slap_bi_head backendInfo = LDAP_STAILQ_HEAD_INITIALIZER(backendInfo);
 
 int			nBackendDB = 0; 
-BackendDB		*backendDB = NULL;
+slap_be_head backendDB = LDAP_STAILQ_HEAD_INITIALIZER(backendDB);
 
 static int
 backend_init_controls( BackendInfo *bi )
@@ -91,26 +91,25 @@ backend_init_controls( BackendInfo *bi )
 int backend_init(void)
 {
 	int rc = -1;
+	BackendInfo *bi;
 
-	if((nBackendInfo != 0) || (backendInfo != NULL)) {
+	if((nBackendInfo != 0) || !LDAP_STAILQ_EMPTY(&backendInfo)) {
 		/* already initialized */
 		Debug( LDAP_DEBUG_ANY,
 			"backend_init: already initialized\n", 0, 0, 0 );
 		return -1;
 	}
 
-	for( ;
-		slap_binfo[nBackendInfo].bi_type != NULL;
-		nBackendInfo++ )
+	for( bi=slap_binfo; bi->bi_type != NULL; bi++,nBackendInfo++ )
 	{
-		assert( slap_binfo[nBackendInfo].bi_init );
+		assert( bi->bi_init );
 
-		rc = slap_binfo[nBackendInfo].bi_init( &slap_binfo[nBackendInfo] );
+		rc = bi->bi_init( bi );
 
 		if(rc != 0) {
 			Debug( LDAP_DEBUG_ANY,
 				"backend_init: initialized for type \"%s\"\n",
-				slap_binfo[nBackendInfo].bi_type, 0, 0 );
+				bi->bi_type, 0, 0 );
 			/* destroy those we've already inited */
 			for( nBackendInfo--;
 				nBackendInfo >= 0 ;
@@ -123,10 +122,10 @@ int backend_init(void)
 			}
 			return rc;
 		}
+		LDAP_STAILQ_INSERT_TAIL(&backendInfo, bi, bi_next);
 	}
 
 	if ( nBackendInfo > 0) {
-		backendInfo = slap_binfo;
 		return 0;
 	}
 
@@ -164,25 +163,9 @@ int backend_add(BackendInfo *aBackendInfo)
 	(void)backend_init_controls( aBackendInfo );
 
 	/* now add the backend type to the Backend Info List */
-	{
-		BackendInfo *newBackendInfo = 0;
-
-		/* if backendInfo == slap_binfo no deallocation of old backendInfo */
-		if (backendInfo == slap_binfo) {
-			newBackendInfo = ch_calloc(nBackendInfo + 1, sizeof(BackendInfo));
-			AC_MEMCPY(newBackendInfo, backendInfo,
-				sizeof(BackendInfo) * nBackendInfo);
-		} else {
-			newBackendInfo = ch_realloc(backendInfo,
-				sizeof(BackendInfo) * (nBackendInfo + 1));
-		}
-
-		AC_MEMCPY(&newBackendInfo[nBackendInfo], aBackendInfo,
-			sizeof(BackendInfo));
-		backendInfo = newBackendInfo;
-		nBackendInfo++;
-		return 0;
-	}
+	LDAP_STAILQ_INSERT_TAIL( &backendInfo, aBackendInfo, bi_next );
+	nBackendInfo++;
+	return 0;
 }
 
 static int
@@ -255,6 +238,7 @@ int backend_startup(Backend *be)
 {
 	int i;
 	int rc = 0;
+	BackendInfo *bi;
 
 	if( ! ( nBackendDB > 0 ) ) {
 		/* no databases */
@@ -291,23 +275,25 @@ int backend_startup(Backend *be)
 	}
 
 	/* open each backend type */
-	for( i = 0; i < nBackendInfo; i++ ) {
-		if( backendInfo[i].bi_nDB == 0) {
+	i = -1;
+	LDAP_STAILQ_FOREACH(bi, &backendInfo, bi_next) {
+		i++;
+		if( bi->bi_nDB == 0) {
 			/* no database of this type, don't open */
 			continue;
 		}
 
-		if( backendInfo[i].bi_open ) {
-			rc = backendInfo[i].bi_open( &backendInfo[i] );
+		if( bi->bi_open ) {
+			rc = bi->bi_open( bi );
 			if ( rc != 0 ) {
 				Debug( LDAP_DEBUG_ANY,
-					"backend_startup: bi_open %d failed!\n",
-					i, 0, 0 );
+					"backend_startup: bi_open %d (%s) failed!\n",
+					i, bi->bi_type, 0 );
 				return rc;
 			}
 		}
 
-		(void)backend_init_controls( &backendInfo[i] );
+		(void)backend_init_controls( bi );
 	}
 
 	ldap_pvt_thread_mutex_init( &slapd_rq.rq_mutex );
@@ -315,26 +301,28 @@ int backend_startup(Backend *be)
 	LDAP_STAILQ_INIT( &slapd_rq.run_list );
 
 	/* open each backend database */
-	for( i = 0; i < nBackendDB; i++ ) {
-		if ( backendDB[i].be_suffix == NULL ) {
+	i = -1;
+	LDAP_STAILQ_FOREACH(be, &backendDB, be_next) {
+		i++;
+		if ( be->be_suffix == NULL ) {
 			Debug( LDAP_DEBUG_ANY,
 				"backend_startup: warning, database %d (%s) "
 				"has no suffix\n",
-				i, backendDB[i].bd_info->bi_type, 0 );
+				i, be->bd_info->bi_type, 0 );
 		}
 		/* append global access controls */
-		acl_append( &backendDB[i].be_acl, frontendDB->be_acl );
+		acl_append( &be->be_acl, frontendDB->be_acl );
 
-		rc = backend_startup_one( &backendDB[i] );
+		rc = backend_startup_one( be );
 
 		if ( rc ) return rc;
 
 
-		if ( backendDB[i].be_syncinfo ) {
+		if ( be->be_syncinfo ) {
 			syncinfo_t *si;
 
-			if ( !( backendDB[i].be_search && backendDB[i].be_add &&
-				backendDB[i].be_modify && backendDB[i].be_delete )) {
+			if ( !( be->be_search && be->be_add &&
+				be->be_modify && be->be_delete )) {
 				Debug( LDAP_DEBUG_ANY,
 					"backend_startup: database(%d) does not support "
 					"operations required for syncrepl", i, 0, 0 );
@@ -342,8 +330,8 @@ int backend_startup(Backend *be)
 			}
 
 			{
-				si = backendDB[i].be_syncinfo;
-				si->si_be = &backendDB[i];
+				si = be->be_syncinfo;
+				si->si_be = be;
 				init_syncrepl( si );
 				ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
 				ldap_pvt_runqueue_insert( &slapd_rq,
@@ -358,12 +346,14 @@ int backend_startup(Backend *be)
 
 int backend_num( Backend *be )
 {
-	int i;
+	int i = 0;
+	BackendDB *b2;
 
 	if( be == NULL ) return -1;
 
-	for( i = 0; i < nBackendDB; i++ ) {
-		if( be == &backendDB[i] ) return i;
+	LDAP_STAILQ_FOREACH( b2, &backendDB, be_next ) {
+		if( be == b2 ) return i;
+		i++;
 	}
 	return -1;
 }
@@ -372,6 +362,7 @@ int backend_shutdown( Backend *be )
 {
 	int i;
 	int rc = 0;
+	BackendInfo *bi;
 
 	if( be != NULL ) {
 		/* shutdown a specific backend database */
@@ -393,29 +384,27 @@ int backend_shutdown( Backend *be )
 	}
 
 	/* close each backend database */
-	for( i = 0; i < nBackendDB; i++ ) {
-		if ( backendDB[i].bd_info->bi_db_close ) {
-			backendDB[i].bd_info->bi_db_close(
-				&backendDB[i] );
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( be->bd_info->bi_db_close ) {
+			be->bd_info->bi_db_close( be );
 		}
 
 		if(rc != 0) {
 			Debug( LDAP_DEBUG_ANY,
 				"backend_close: bi_db_close %s failed!\n",
-				backendDB[i].be_type, 0, 0 );
+				be->be_type, 0, 0 );
 		}
 	}
 
 	/* close each backend type */
-	for( i = 0; i < nBackendInfo; i++ ) {
-		if( backendInfo[i].bi_nDB == 0 ) {
+	LDAP_STAILQ_FOREACH( bi, &backendInfo, bi_next ) {
+		if( bi->bi_nDB == 0 ) {
 			/* no database of this type */
 			continue;
 		}
 
-		if( backendInfo[i].bi_close ) {
-			backendInfo[i].bi_close(
-				&backendInfo[i] );
+		if( bi->bi_close ) {
+			bi->bi_close( bi );
 		}
 	}
 
@@ -436,10 +425,12 @@ int backend_destroy(void)
 {
 	int i;
 	BackendDB *bd;
+	BackendInfo *bi;
 	struct slap_csn_entry *csne;
 
 	/* destroy each backend database */
-	for( i = 0, bd = backendDB; i < nBackendDB; i++, bd++ ) {
+	while (( bd = LDAP_STAILQ_FIRST(&backendDB))) {
+		LDAP_STAILQ_REMOVE_HEAD(&backendDB, be_next);
 
 		if ( bd->be_syncinfo ) {
 			syncinfo_free( bd->be_syncinfo );
@@ -472,25 +463,18 @@ int backend_destroy(void)
 			free( bd->be_rootpw.bv_val );
 		}
 		acl_destroy( bd->be_acl, frontendDB->be_acl );
+		free( bd );
 	}
-	free( backendDB );
 
 	/* destroy each backend type */
-	for( i = 0; i < nBackendInfo; i++ ) {
-		if( backendInfo[i].bi_destroy ) {
-			backendInfo[i].bi_destroy(
-				&backendInfo[i] );
+	LDAP_STAILQ_FOREACH( bi, &backendInfo, bi_next ) {
+		if( bi->bi_destroy ) {
+			bi->bi_destroy( bi );
 		}
 	}
 
-#ifdef SLAPD_MODULES
-	if (backendInfo != slap_binfo) {
-	   free(backendInfo);
-	}
-#endif /* SLAPD_MODULES */
-
 	nBackendInfo = 0;
-	backendInfo = NULL;
+	LDAP_STAILQ_INIT(&backendInfo);
 
 	/* destroy frontend database */
 	bd = frontendDB;
@@ -517,12 +501,12 @@ int backend_destroy(void)
 
 BackendInfo* backend_info(const char *type)
 {
-	int i;
+	BackendInfo *bi;
 
 	/* search for the backend type */
-	for( i = 0; i < nBackendInfo; i++ ) {
-		if( strcasecmp(backendInfo[i].bi_type, type) == 0 ) {
-			return &backendInfo[i];
+	LDAP_STAILQ_FOREACH(bi,&backendInfo,bi_next) {
+		if( strcasecmp(bi->bi_type, type) == 0 ) {
+			return bi;
 		}
 	}
 
@@ -543,23 +527,9 @@ backend_db_init(
 		return NULL;
 	}
 
-	be = backendDB;
-
-	backendDB = (BackendDB *) ch_realloc(
-			(char *) backendDB,
-		    (nBackendDB + 1) * sizeof(Backend) );
-
-	memset( &backendDB[nbackends], '\0', sizeof(Backend) );
-
-	/* did realloc move our table? if so, fix up dependent pointers */
-	if ( be != backendDB ) {
-		int i;
-		for ( i=0, be=backendDB; i<nbackends; i++, be++ ) {
-			be->be_pcl_mutexp = &be->be_pcl_mutex;
-		}
-	}
-
-	be = &backends[nbackends++];
+	be = ch_calloc( 1, sizeof(Backend) );
+	nbackends++;
+	LDAP_STAILQ_INSERT_TAIL(&backendDB, be, be_next);
 
 	be->bd_info = bi;
 
@@ -593,11 +563,12 @@ backend_db_init(
 void
 be_db_close( void )
 {
+	BackendDB *be;
 	int	i;
 
-	for ( i = 0; i < nbackends; i++ ) {
-		if ( backends[i].bd_info->bi_db_close ) {
-			(*backends[i].bd_info->bi_db_close)( &backends[i] );
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( be->bd_info->bi_db_close ) {
+			be->bd_info->bi_db_close( be );
 		}
 	}
 
@@ -615,22 +586,21 @@ select_backend(
 {
 	int		i, j;
 	ber_len_t	len, dnlen = dn->bv_len;
-	Backend		*be = NULL;
+	Backend		*be, *b2;
 
-	for ( i = 0; i < nbackends; i++ ) {
-		if ( backends[i].be_nsuffix == NULL ) {
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( be->be_nsuffix == NULL ) {
 			continue;
 		}
 
-		for ( j = 0; !BER_BVISNULL( &backends[i].be_nsuffix[j] ); j++ )
+		for ( j = 0; !BER_BVISNULL( &be->be_nsuffix[j] ); j++ )
 		{
-			if ( ( SLAP_GLUE_SUBORDINATE( &backends[i] ) )
-				&& noSubs )
+			if ( ( SLAP_GLUE_SUBORDINATE( be ) ) && noSubs )
 			{
 			  	continue;
 			}
 
-			len = backends[i].be_nsuffix[j].bv_len;
+			len = be->be_nsuffix[j].bv_len;
 
 			if ( len > dnlen ) {
 				/* suffix is longer than DN */
@@ -647,25 +617,25 @@ select_backend(
 				continue;
 			}
 
-			if ( strcmp( backends[i].be_nsuffix[j].bv_val,
+			if ( strcmp( be->be_nsuffix[j].bv_val,
 				&dn->bv_val[dnlen-len] ) == 0 )
 			{
-				if( be == NULL ) {
-					be = &backends[i];
+				if( b2 == NULL ) {
+					b2 = be;
 
 					if( manageDSAit && len == dnlen &&
 						!SLAP_GLUE_SUBORDINATE( be ) ) {
 						continue;
 					}
 				} else {
-					be = &backends[i];
+					b2 = be;
 				}
-				return be;
+				return b2;
 			}
 		}
 	}
 
-	return be;
+	return b2;
 }
 
 int
@@ -780,15 +750,16 @@ be_entry_release_rw(
 int
 backend_unbind( Operation *op, SlapReply *rs )
 {
-	int		i;
+	int		i = 0;
+	BackendDB *be;
 
-	for ( i = 0; i < nbackends; i++ ) {
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
 #if defined( LDAP_SLAPI )
 		if ( op->o_pb ) {
 			int rc;
 			if ( i == 0 ) slapi_int_pblock_set_operation( op->o_pb, op );
-			slapi_pblock_set( op->o_pb, SLAPI_BACKEND, (void *)&backends[i] );
-			rc = slapi_int_call_plugins( &backends[i],
+			slapi_pblock_set( op->o_pb, SLAPI_BACKEND, (void *)be );
+			rc = slapi_int_call_plugins( be,
 				SLAPI_PLUGIN_PRE_UNBIND_FN, (Slapi_PBlock *)op->o_pb );
 			if ( rc < 0 ) {
 				/*
@@ -803,13 +774,13 @@ backend_unbind( Operation *op, SlapReply *rs )
 		}
 #endif /* defined( LDAP_SLAPI ) */
 
-		if ( backends[i].be_unbind ) {
-			op->o_bd = &backends[i];
-			(*backends[i].be_unbind)( op, rs );
+		if ( be->be_unbind ) {
+			op->o_bd = be;
+			be->be_unbind( op, rs );
 		}
 
 #if defined( LDAP_SLAPI )
-		if ( op->o_pb != NULL && slapi_int_call_plugins( &backends[i],
+		if ( op->o_pb != NULL && slapi_int_call_plugins( be,
 			SLAPI_PLUGIN_POST_UNBIND_FN, (Slapi_PBlock *)op->o_pb ) < 0 )
 		{
 			Debug(LDAP_DEBUG_TRACE,
@@ -817,6 +788,7 @@ backend_unbind( Operation *op, SlapReply *rs )
 				0, 0, 0);
 		}
 #endif /* defined( LDAP_SLAPI ) */
+		i++;
 	}
 
 	return 0;
@@ -826,11 +798,11 @@ int
 backend_connection_init(
 	Connection   *conn )
 {
-	int	i;
+	BackendDB *be;
 
-	for ( i = 0; i < nbackends; i++ ) {
-		if ( backends[i].be_connection_init ) {
-			(*backends[i].be_connection_init)( &backends[i], conn);
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( be->be_connection_init ) {
+			be->be_connection_init( be, conn);
 		}
 	}
 
@@ -841,11 +813,11 @@ int
 backend_connection_destroy(
 	Connection   *conn )
 {
-	int	i;
+	BackendDB *be;
 
-	for ( i = 0; i < nbackends; i++ ) {
-		if ( backends[i].be_connection_destroy ) {
-			(*backends[i].be_connection_destroy)( &backends[i], conn);
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( be->be_connection_destroy ) {
+			be->be_connection_destroy( be, conn);
 		}
 	}
 
diff --git a/servers/slapd/backover.c b/servers/slapd/backover.c
index e1b31a50c1..f4b82dc0be 100644
--- a/servers/slapd/backover.c
+++ b/servers/slapd/backover.c
@@ -545,12 +545,10 @@ overlay_register_control( BackendDB *be, const char *oid )
 	}
 
 	if ( SLAP_DBFLAGS( be ) & SLAP_DBFLAG_GLOBAL_OVERLAY ) {
-		int	i;
+		BackendDB *bd;
 		
 		/* add to all backends... */
-		for ( i = 0; i < nBackendDB; i++ ) {
-			BackendDB	*bd = &backendDB[i];
-			
+		LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
 			if ( be == bd ) {
 				gotit = 1;
 			}
diff --git a/servers/slapd/bconfig.c b/servers/slapd/bconfig.c
index b09b3afb2f..f208a5d033 100644
--- a/servers/slapd/bconfig.c
+++ b/servers/slapd/bconfig.c
@@ -893,7 +893,7 @@ config_generic(ConfigArgs *c) {
 			/* NOTE: config is always the first backend!
 			 */
 			if ( !strcasecmp( c->argv[1], "config" )) {
-				c->be = backendDB;
+				c->be = LDAP_STAILQ_FIRST(&backendDB);
 			} else if ( !strcasecmp( c->argv[1], "frontend" )) {
 				c->be = frontendDB;
 			} else if(!(c->be = backend_db_init(c->argv[1]))) {
@@ -3166,7 +3166,7 @@ config_add_internal( CfBackInfo *cfb, Entry *e, SlapReply *rs, int *renum )
 			goto ok;
 		/* FALLTHRU */
 	case Cft_Global:
-		ca.be = backendDB;
+		ca.be = LDAP_STAILQ_FIRST(&backendDB);
 		break;
 
 	case Cft_Backend:
@@ -3764,8 +3764,7 @@ config_back_db_open( BackendDB *be )
 	 */
 	
 	c.line = 0;
-	bi = backendInfo;
-	for (i=0; i<nBackendInfo; i++, bi++) {
+	LDAP_STAILQ_FOREACH( bi, &backendInfo, bi_next) {
 		if (!bi->bi_cf_table) continue;
 		if (!bi->bi_private) continue;
 
@@ -3788,12 +3787,14 @@ config_back_db_open( BackendDB *be )
 	}
 
 	/* Create database nodes... */
-	for (i=0; i<nBackendDB; i++) {
+	i = -1;
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
 		slap_overinfo *oi = NULL;
+		i++;
 		if ( i == 0 ) {
 			bptr = frontendDB;
 		} else {
-			bptr = &backendDB[i];
+			bptr = be;
 		}
 		if ( overlay_is_over( bptr )) {
 			oi = bptr->bd_info->bi_private;
diff --git a/servers/slapd/cancel.c b/servers/slapd/cancel.c
index e1256de909..141229b874 100644
--- a/servers/slapd/cancel.c
+++ b/servers/slapd/cancel.c
@@ -90,8 +90,7 @@ int cancel_extop( Operation *op, SlapReply *rs )
 
 		o->o_cancel = SLAP_CANCEL_REQ;
 
-		for ( i = 0; i < nbackends; i++ ) {
-			op->o_bd = &backends[i];
+		LDAP_STAILQ_FOREACH( op->o_bd, &backendDB, be_next ) {
 			if( !op->o_bd->be_cancel ) continue;
 
 			op->oq_cancel.rs_msgid = opid;
diff --git a/servers/slapd/config.h b/servers/slapd/config.h
index 15d41f2349..be90c5c2d3 100644
--- a/servers/slapd/config.h
+++ b/servers/slapd/config.h
@@ -72,6 +72,12 @@ typedef struct ConfigOCs {
 	char *def;
 	ConfigType cft;
 	ObjectClass **oc;
+#if 0
+	BI_op_add *add;		/* optional, add-specific processing */
+	BI_op_delete *del;	/* mandatory, delete implementation */
+	BI_op_modify *mod;	/* optional, mod-specific */
+	BI_op_modrdn *ren;	/* optional, modrdn... */
+#endif
 } ConfigOCs;
 
 typedef struct config_args_s {
diff --git a/servers/slapd/overlays/glue.c b/servers/slapd/overlays/glue.c
index 13da05a952..957a45655d 100644
--- a/servers/slapd/overlays/glue.c
+++ b/servers/slapd/overlays/glue.c
@@ -40,7 +40,6 @@
 
 typedef struct gluenode {
 	BackendDB *gn_be;
-	int	gn_bx;
 	struct berval gn_pdn;
 	int gn_async;
 } gluenode;
@@ -730,23 +729,6 @@ glue_db_destroy (
 	return SLAP_CB_CONTINUE;
 }
 
-static int
-glue_db_open (
-	BackendDB *be
-)
-{
-	slap_overinst	*on = (slap_overinst *)be->bd_info;
-	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
-	int i;
-
-	for ( i=0; i<gi->gi_nodes; i++ ) {
-		int j;
-
-		gi->gi_n[i].gn_be = backendDB + gi->gi_n[i].gn_bx;
-	}
-	return 0;
-}
-
 static int
 glue_db_close( 
 	BackendDB *be
@@ -813,7 +795,7 @@ glue_db_config(
 		}
 		gi = (glueinfo *)ch_realloc( gi, sizeof(glueinfo) +
 			gi->gi_nodes * sizeof(gluenode));
-		gi->gi_n[gi->gi_nodes].gn_bx = b2 - backendDB;
+		gi->gi_n[gi->gi_nodes].gn_be = b2;
 		dnParent( &b2->be_nsuffix[0], &gi->gi_n[gi->gi_nodes].gn_pdn );
 		gi->gi_n[gi->gi_nodes].gn_async = async;
 		gi->gi_nodes++;
@@ -830,7 +812,6 @@ glue_init()
 
 	glue.on_bi.bi_db_init = glue_db_init;
 	glue.on_bi.bi_db_config = glue_db_config;
-	glue.on_bi.bi_db_open = glue_db_open;
 	glue.on_bi.bi_db_close = glue_db_close;
 	glue.on_bi.bi_db_destroy = glue_db_destroy;
 
diff --git a/servers/slapd/root_dse.c b/servers/slapd/root_dse.c
index dbe4f371c6..057b9061e9 100644
--- a/servers/slapd/root_dse.c
+++ b/servers/slapd/root_dse.c
@@ -56,6 +56,7 @@ root_dse_info(
 	struct berval nvals[2];
 	int		i, j;
 	char ** supportedSASLMechanisms;
+	BackendDB *be;
 
 	AttributeDescription *ad_structuralObjectClass
 		= slap_schema.si_ad_structuralObjectClass;
@@ -116,34 +117,34 @@ root_dse_info(
 		return LDAP_OTHER;
 	}
 
-	for ( i = 0; i < nbackends; i++ ) {
-		if ( backends[i].be_suffix == NULL
-				|| backends[i].be_nsuffix == NULL ) {
+	LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+		if ( be->be_suffix == NULL
+				|| be->be_nsuffix == NULL ) {
 			/* no suffix! */
 			continue;
 		}
-		if ( SLAP_MONITOR( &backends[i] )) {
-			vals[0] = backends[i].be_suffix[0];
-			nvals[0] = backends[i].be_nsuffix[0];
+		if ( SLAP_MONITOR( be )) {
+			vals[0] = be->be_suffix[0];
+			nvals[0] = be->be_nsuffix[0];
 			if( attr_merge( e, ad_monitorContext, vals, nvals ) ) {
 				return LDAP_OTHER;
 			}
 			continue;
 		}
-		if ( SLAP_CONFIG( &backends[i] )) {
-			vals[0] = backends[i].be_suffix[0];
-			nvals[0] = backends[i].be_nsuffix[0];
+		if ( SLAP_CONFIG( be )) {
+			vals[0] = be->be_suffix[0];
+			nvals[0] = be->be_nsuffix[0];
 			if( attr_merge( e, ad_configContext, vals, nvals ) ) {
 				return LDAP_OTHER;
 			}
 			continue;
 		}
-		if ( SLAP_GLUE_SUBORDINATE( &backends[i] ) && !SLAP_GLUE_ADVERTISE( &backends[i] ) ) {
+		if ( SLAP_GLUE_SUBORDINATE( be ) && !SLAP_GLUE_ADVERTISE( be ) ) {
 			continue;
 		}
-		for ( j = 0; backends[i].be_suffix[j].bv_val != NULL; j++ ) {
-			vals[0] = backends[i].be_suffix[j];
-			nvals[0] = backends[i].be_nsuffix[0];
+		for ( j = 0; be->be_suffix[j].bv_val != NULL; j++ ) {
+			vals[0] = be->be_suffix[j];
+			nvals[0] = be->be_nsuffix[0];
 			if( attr_merge( e, ad_namingContexts, vals, nvals ) ) {
 				return LDAP_OTHER;
 			}
diff --git a/servers/slapd/slap.h b/servers/slapd/slap.h
index a419a94103..28b63a4c9c 100644
--- a/servers/slapd/slap.h
+++ b/servers/slapd/slap.h
@@ -1389,11 +1389,13 @@ typedef struct slap_acl_state {
 
 typedef struct slap_backend_info BackendInfo;	/* per backend type */
 typedef struct slap_backend_db BackendDB;		/* per backend database */
+typedef LDAP_STAILQ_HEAD(BeI, slap_backend_info) slap_bi_head;
+typedef LDAP_STAILQ_HEAD(BeDB, slap_backend_db) slap_be_head;
 
 LDAP_SLAPD_V (int) nBackendInfo;
 LDAP_SLAPD_V (int) nBackendDB;
-LDAP_SLAPD_V (BackendInfo *) backendInfo;
-LDAP_SLAPD_V (BackendDB *) backendDB;
+LDAP_SLAPD_V (slap_bi_head) backendInfo;
+LDAP_SLAPD_V (slap_be_head) backendDB;
 LDAP_SLAPD_V (BackendDB *) frontendDB;
 
 LDAP_SLAPD_V (int) slapMode;	
@@ -1736,6 +1738,7 @@ struct slap_backend_db {
 	struct ConfigTable *be_cf_table;
 
 	void	*be_private;	/* anything the backend database needs 	   */
+	LDAP_STAILQ_ENTRY(slap_backend_db) be_next;
 };
 
 struct slap_conn;
@@ -2068,6 +2071,7 @@ struct slap_backend_info {
 	unsigned int bi_nDB;	/* number of databases of this type */
 	struct ConfigTable *bi_cf_table;
 	void	*bi_private;	/* anything the backend type needs */
+	LDAP_STAILQ_ENTRY(slap_backend_info) bi_next ;
 };
 
 #define c_authtype	c_authz.sai_method
@@ -2921,11 +2925,10 @@ struct zone_heap {
 #endif
 
 #define SLAP_BACKEND_INIT_MODULE(b) \
+	static BackendInfo bi;	\
 	int \
 	init_module( int argc, char *argv[] ) \
 	{ \
-		BackendInfo bi; \
-		memset( &bi, '\0', sizeof( bi ) ); \
 		bi.bi_type = #b ; \
 		bi.bi_init = b ## _back_initialize; \
 		backend_add( &bi ); \
diff --git a/servers/slapd/slapcommon.c b/servers/slapd/slapcommon.c
index 4a0c55a600..ab0048db05 100644
--- a/servers/slapd/slapcommon.c
+++ b/servers/slapd/slapcommon.c
@@ -446,21 +446,24 @@ slap_tool_init(
 			fprintf( stderr, "No available databases\n" );
 			exit( EXIT_FAILURE );
 		}
+		LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+			dbnum++;
+			if ( dbnum < 1 ) continue;
 		
-		be = &backends[dbnum=1];
+		 	if ( SLAP_MONITOR(be))
+				continue;
+
 		/* If just doing the first by default and it is a
 		 * glue subordinate, find the master.
 		 */
-		while (SLAP_GLUE_SUBORDINATE(be) || SLAP_MONITOR(be)) {
-			if (SLAP_GLUE_SUBORDINATE(be)) {
+			if ( SLAP_GLUE_SUBORDINATE(be) ) {
 				nosubordinates = 1;
+				continue;
 			}
-			be++;
-			dbnum++;
+			break;
 		}
 
-
-		if ( dbnum >= nbackends ) {
+		if ( !be ) {
 			fprintf( stderr, "Available database(s) "
 					"do not allow %s\n", progname );
 			exit( EXIT_FAILURE );
@@ -482,7 +485,10 @@ slap_tool_init(
 		exit( EXIT_FAILURE );
 
 	} else {
-		be = &backends[dbnum];
+		LDAP_STAILQ_FOREACH( be, &backendDB, be_next ) {
+			if ( dbnum == 0 ) break;
+			dbnum--;
+		}
 	}
 
 startup:;
-- 
2.39.5