From e93e318629050cb7fc89e16fd5d6c1360681ff4f Mon Sep 17 00:00:00 2001
From: Kurt Zeilenga <kurt@openldap.org>
Date: Wed, 21 Dec 2005 21:06:26 +0000
Subject: [PATCH] Sync back-bdb with HEAD

---
 servers/slapd/back-bdb/add.c      |  37 ++----
 servers/slapd/back-bdb/back-bdb.h |   7 +-
 servers/slapd/back-bdb/bind.c     |   2 -
 servers/slapd/back-bdb/cache.c    | 198 ++++++++++++++++++------------
 servers/slapd/back-bdb/config.c   |   8 +-
 servers/slapd/back-bdb/delete.c   |  37 ++++--
 servers/slapd/back-bdb/init.c     |  19 +--
 servers/slapd/back-bdb/modify.c   |  19 ++-
 servers/slapd/back-bdb/modrdn.c   |  15 +--
 servers/slapd/back-bdb/search.c   |  30 ++---
 servers/slapd/back-bdb/tools.c    |  39 +-----
 servers/slapd/modrdn.c            |  33 ++++-
 servers/slapd/proto-slap.h        |   6 +-
 13 files changed, 247 insertions(+), 203 deletions(-)

diff --git a/servers/slapd/back-bdb/add.c b/servers/slapd/back-bdb/add.c
index a7273ef7c7..c9eb98c816 100644
--- a/servers/slapd/back-bdb/add.c
+++ b/servers/slapd/back-bdb/add.c
@@ -34,9 +34,7 @@ bdb_add(Operation *op, SlapReply *rs )
 	AttributeDescription *entry = slap_schema.si_ad_entry;
 	DB_TXN		*ltid = NULL, *lt2;
 	struct bdb_op_info opinfo = {0};
-#ifdef BDB_SUBENTRIES
 	int subentry;
-#endif
 	u_int32_t	locker = 0;
 	DB_LOCK		lock;
 
@@ -65,9 +63,7 @@ bdb_add(Operation *op, SlapReply *rs )
 		goto return_results;
 	}
 
-#ifdef BDB_SUBENTRIES
 	subentry = is_entry_subentry( op->oq_add.rs_e );
-#endif
 
 	/*
 	 * acquire an ID outside of the operation transaction
@@ -196,7 +192,6 @@ retry:	/* transaction retry */
 			goto return_results;;
 		}
 
-#ifdef BDB_SUBENTRIES
 		if ( is_entry_subentry( p ) ) {
 			/* parent is a subentry, don't allow add */
 			Debug( LDAP_DEBUG_TRACE,
@@ -206,7 +201,6 @@ retry:	/* transaction retry */
 			rs->sr_text = "parent is a subentry";
 			goto return_results;;
 		}
-#endif
 		if ( is_entry_alias( p ) ) {
 			/* parent is an alias, don't allow add */
 			Debug( LDAP_DEBUG_TRACE,
@@ -233,12 +227,10 @@ retry:	/* transaction retry */
 			goto return_results;
 		}
 
-#ifdef BDB_SUBENTRIES
 		if ( subentry ) {
 			/* FIXME: */
 			/* parent must be an administrative point of the required kind */
 		}
-#endif
 
 		/* free parent and reader lock */
 		bdb_unlocked_cache_return_entry_r( &bdb->bi_cache, p );
@@ -261,14 +253,6 @@ retry:	/* transaction retry */
 		}
 	}
 
-	if ( get_assert( op ) &&
-		( test_filter( op, op->oq_add.rs_e, get_assertion( op ))
-			!= LDAP_COMPARE_TRUE ))
-	{
-		rs->sr_err = LDAP_ASSERTION_FAILED;
-		goto return_results;
-	}
-
 	rs->sr_err = access_allowed( op, op->oq_add.rs_e,
 		entry, NULL, ACL_WADD, NULL );
 
@@ -320,11 +304,11 @@ retry:	/* transaction retry */
 		goto return_results;
 	}
 
-	/* id2entry index */
-	rs->sr_err = bdb_id2entry_add( op->o_bd, lt2, op->oq_add.rs_e );
-	if ( rs->sr_err != 0 ) {
+	/* attribute indexes */
+	rs->sr_err = bdb_index_entry_add( op, lt2, op->oq_add.rs_e );
+	if ( rs->sr_err != LDAP_SUCCESS ) {
 		Debug( LDAP_DEBUG_TRACE,
-			LDAP_XSTRING(bdb_add) ": id2entry_add failed\n",
+			LDAP_XSTRING(bdb_add) ": index_entry_add failed\n",
 			0, 0, 0 );
 		switch( rs->sr_err ) {
 		case DB_LOCK_DEADLOCK:
@@ -333,15 +317,15 @@ retry:	/* transaction retry */
 		default:
 			rs->sr_err = LDAP_OTHER;
 		}
-		rs->sr_text = "entry store failed";
+		rs->sr_text = "index generation failed";
 		goto return_results;
 	}
 
-	/* attribute indexes */
-	rs->sr_err = bdb_index_entry_add( op, lt2, op->oq_add.rs_e );
-	if ( rs->sr_err != LDAP_SUCCESS ) {
+	/* id2entry index */
+	rs->sr_err = bdb_id2entry_add( op->o_bd, lt2, op->oq_add.rs_e );
+	if ( rs->sr_err != 0 ) {
 		Debug( LDAP_DEBUG_TRACE,
-			LDAP_XSTRING(bdb_add) ": index_entry_add failed\n",
+			LDAP_XSTRING(bdb_add) ": id2entry_add failed\n",
 			0, 0, 0 );
 		switch( rs->sr_err ) {
 		case DB_LOCK_DEADLOCK:
@@ -350,9 +334,10 @@ retry:	/* transaction retry */
 		default:
 			rs->sr_err = LDAP_OTHER;
 		}
-		rs->sr_text = "index generation failed";
+		rs->sr_text = "entry store failed";
 		goto return_results;
 	}
+
 	if ( TXN_COMMIT( lt2, 0 ) != 0 ) {
 		rs->sr_err = LDAP_OTHER;
 		rs->sr_text = "txn_commit(2) failed";
diff --git a/servers/slapd/back-bdb/back-bdb.h b/servers/slapd/back-bdb/back-bdb.h
index 854a9b80ff..7190b4d844 100644
--- a/servers/slapd/back-bdb/back-bdb.h
+++ b/servers/slapd/back-bdb/back-bdb.h
@@ -26,8 +26,6 @@ LDAP_BEGIN_DECL
 
 #define DB_VERSION_FULL ((DB_VERSION_MAJOR << 24) | (DB_VERSION_MINOR << 16) | DB_VERSION_PATCH)
 
-#define BDB_SUBENTRIES 1
-
 #define DN_BASE_PREFIX		SLAP_INDEX_EQUALITY_PREFIX
 #define DN_ONE_PREFIX	 	'%'
 #define DN_SUBTREE_PREFIX 	'@'
@@ -125,6 +123,7 @@ typedef struct bdb_entry_info {
 typedef struct bdb_cache {
 	int             c_maxsize;
 	int             c_cursize;
+	int		c_minfree;
 	int		c_eiused;	/* EntryInfo's in use */
 	int		c_leaves;	/* EntryInfo leaf nodes */
 	EntryInfo	c_dntree;
@@ -133,7 +132,8 @@ typedef struct bdb_cache {
 	EntryInfo	*c_lruhead;	/* lru - add accessed entries here */
 	EntryInfo	*c_lrutail;	/* lru - rem lru entries from here */
 	ldap_pvt_thread_rdwr_t c_rwlock;
-	ldap_pvt_thread_mutex_t lru_mutex;
+	ldap_pvt_thread_mutex_t lru_head_mutex;
+	ldap_pvt_thread_mutex_t lru_tail_mutex;
 	u_int32_t	c_locker;	/* used by lru cleaner */
 #ifdef SLAP_ZONE_ALLOC
 	void *c_zctx;
@@ -177,6 +177,7 @@ struct bdb_info {
 	u_int32_t	bi_txn_cp_kbyte;
 	void		*bi_txn_cp_task;
 	void		*bi_index_task;
+ 	void		*bi_cache_task;
 
 	int			bi_lock_detect;
 	long		bi_shm_key;
diff --git a/servers/slapd/back-bdb/bind.c b/servers/slapd/back-bdb/bind.c
index 69d3756462..ed76a6283f 100644
--- a/servers/slapd/back-bdb/bind.c
+++ b/servers/slapd/back-bdb/bind.c
@@ -104,7 +104,6 @@ dn2entry_retry:
 	ber_dupbv( &op->oq_bind.rb_edn, &e->e_name );
 
 	/* check for deleted */
-#ifdef BDB_SUBENTRIES
 	if ( is_entry_subentry( e ) ) {
 		/* entry is an subentry, don't allow bind */
 		Debug( LDAP_DEBUG_TRACE, "entry is subentry\n", 0,
@@ -112,7 +111,6 @@ dn2entry_retry:
 		rs->sr_err = LDAP_INVALID_CREDENTIALS;
 		goto done;
 	}
-#endif
 
 	if ( is_entry_alias( e ) ) {
 		/* entry is an alias, don't allow bind */
diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index 92711b243b..4c4f7418ff 100644
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -26,9 +26,12 @@
 
 #include "back-bdb.h"
 
+#include "ldap_rq.h"
+
 #ifdef BDB_HIER
 #define bdb_cache_lru_add	hdb_cache_lru_add
 #endif
+static void bdb_cache_lru_add( struct bdb_info *bdb, EntryInfo *ei );
 
 static int	bdb_cache_delete_internal(Cache *cache, EntryInfo *e, int decr);
 #ifdef LDAP_DEBUG
@@ -460,9 +463,8 @@ hdb_cache_find_parent(
 		ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
 
 		if ( addlru ) {
-			ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
-			LRU_ADD( &bdb->bi_cache, ein );
-			ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_mutex );
+			ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_head_mutex );
+			bdb_cache_lru_add( bdb, ein );
 		}
 		addlru = 1;
 
@@ -527,94 +529,131 @@ int hdb_cache_load(
 }
 #endif
 
-/* caller must have lru_mutex locked. mutex
- * will be unlocked on return.
- */
-static void
-bdb_cache_lru_add(
-	struct bdb_info *bdb,
-	u_int32_t	locker,
-	EntryInfo *ei )
+static void *
+bdb_cache_lru_purge(void *ctx, void *arg)
 {
+	struct re_s *rtask = arg;
+	struct bdb_info *bdb = rtask->arg;
 	DB_LOCK		lock, *lockp;
+	EntryInfo *elru, *elprev;
+	int count = 0;
 
-	if ( locker ) {
+	if ( bdb->bi_cache.c_locker ) {
 		lockp = &lock;
 	} else {
 		lockp = NULL;
 	}
 
-	/* See if we're above the cache size limit */
-	if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
-		EntryInfo *elru, *elprev;
-		int i = 0;
-
-		/* Look for an unused entry to remove */
-		for (elru = bdb->bi_cache.c_lrutail; elru; elru = elprev, i++ ) {
-			elprev = elru->bei_lruprev;
+	ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_tail_mutex );
 
-			/* Too many probes, not enough idle, give up */
-			if (i > 10)
-				break;
+	/* Look for an unused entry to remove */
+	for (elru = bdb->bi_cache.c_lrutail; elru; elru = elprev ) {
+		elprev = elru->bei_lruprev;
 
-			/* If we can successfully writelock it, then
-			 * the object is idle.
-			 */
-			if ( bdb_cache_entry_db_lock( bdb->bi_dbenv,
-					bdb->bi_cache.c_locker, elru, 1, 1, lockp ) == 0 ) {
+		/* If we can successfully writelock it, then
+		 * the object is idle.
+		 */
+		if ( bdb_cache_entry_db_lock( bdb->bi_dbenv,
+				bdb->bi_cache.c_locker, elru, 1, 1, lockp ) == 0 ) {
 
-				int stop = 0, decr = 0;
+			int stop = 0;
 
-				/* If this node is in the process of linking into the cache,
-				 * or this node is being deleted, skip it.
-				 */
-				if ( elru->bei_state &
-					( CACHE_ENTRY_NOT_LINKED | CACHE_ENTRY_DELETED )) {
-					bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
-					continue;
-				}
-				/* Free entry for this node if it's present */
-				if ( elru->bei_e ) {
-					elru->bei_e->e_private = NULL;
+			/* If this node is in the process of linking into the cache,
+			 * or this node is being deleted, skip it.
+			 */
+			if ( elru->bei_state &
+				( CACHE_ENTRY_NOT_LINKED | CACHE_ENTRY_DELETED )) {
+				bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
+				continue;
+			}
+			/* Free entry for this node if it's present */
+			if ( elru->bei_e ) {
+				elru->bei_e->e_private = NULL;
 #ifdef SLAP_ZONE_ALLOC
-					bdb_entry_return( bdb, elru->bei_e, elru->bei_zseq );
+				bdb_entry_return( bdb, elru->bei_e, elru->bei_zseq );
 #else
-					bdb_entry_return( elru->bei_e );
+				bdb_entry_return( elru->bei_e );
 #endif
-					elru->bei_e = NULL;
-					decr = 1;
-				}
-				/* ITS#4010 if we're in slapcat, and this node is a leaf
-				 * node, free it.
-				 *
-				 * FIXME: we need to do this for slapd as well, (which is
-				 * why we compute bi_cache.c_leaves now) but at the moment
-				 * we can't because it causes unresolvable deadlocks. 
-				 */
-				if ( slapMode & SLAP_TOOL_READONLY ) {
-					if ( !elru->bei_kids ) {
-						/* This does LRU_DELETE for us */
-						bdb_cache_delete_internal( &bdb->bi_cache, elru, 0 );
-						bdb_cache_delete_cleanup( &bdb->bi_cache, elru );
-					}
-					/* Leave node on LRU list for a future pass */
-				} else {
-					LRU_DELETE( &bdb->bi_cache, elru );
+				elru->bei_e = NULL;
+				count++;
+			}
+			/* ITS#4010 if we're in slapcat, and this node is a leaf
+			 * node, free it.
+			 *
+			 * FIXME: we need to do this for slapd as well, (which is
+			 * why we compute bi_cache.c_leaves now) but at the moment
+			 * we can't because it causes unresolvable deadlocks. 
+			 */
+			if ( slapMode & SLAP_TOOL_READONLY ) {
+				if ( !elru->bei_kids ) {
+					/* This does LRU_DELETE for us */
+					bdb_cache_delete_internal( &bdb->bi_cache, elru, 0 );
+					bdb_cache_delete_cleanup( &bdb->bi_cache, elru );
 				}
-				bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
+				/* Leave node on LRU list for a future pass */
+			} else {
+				LRU_DELETE( &bdb->bi_cache, elru );
+			}
+			bdb_cache_entry_db_unlock( bdb->bi_dbenv, lockp );
 
+			if ( count == bdb->bi_cache.c_minfree ) {
 				ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
-				if ( decr )
-					--bdb->bi_cache.c_cursize;
-				if (bdb->bi_cache.c_cursize <= bdb->bi_cache.c_maxsize)
+				bdb->bi_cache.c_cursize -= bdb->bi_cache.c_minfree;
+				if ( bdb->bi_cache.c_maxsize - bdb->bi_cache.c_cursize >=
+					bdb->bi_cache.c_minfree )
 					stop = 1;
+				count = 0;
 				ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
-				if (stop) break;
 			}
+			if (stop) break;
+		}
+	}
+
+	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_tail_mutex );
+
+	/* If we're running as a task, drop the task */
+	if ( ctx ) {
+		ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
+		ldap_pvt_runqueue_stoptask( &slapd_rq, rtask );
+		/* Defer processing till we're needed again */
+		ldap_pvt_runqueue_resched( &slapd_rq, rtask, 1 );
+		ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
 		}
 	}
+
+/* caller must have lru_head_mutex locked. mutex
+ * will be unlocked on return.
+ */
+static void
+bdb_cache_lru_add(
+	struct bdb_info *bdb,
+	EntryInfo *ei )
+{
 	LRU_ADD( &bdb->bi_cache, ei );
-	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_mutex );
+	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_head_mutex );
+
+	/* See if we're above the cache size limit */
+	if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
+		if ( slapMode & SLAP_TOOL_MODE ) {
+			struct re_s rtask;
+
+			rtask.arg = bdb;
+			bdb_cache_lru_purge( NULL, &rtask );
+		} else {
+			ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
+			if ( bdb->bi_cache_task ) {
+				if ( !ldap_pvt_runqueue_isrunning( &slapd_rq,
+					bdb->bi_cache_task ))
+					ldap_pvt_runqueue_resched( &slapd_rq, bdb->bi_cache_task,
+						0 );
+			} else {
+				bdb->bi_cache_task = ldap_pvt_runqueue_insert( &slapd_rq, 0,
+					bdb_cache_lru_purge, bdb, "bdb_cache_lru_purge",
+					bdb->bi_dbenv_home );
+			}
+			ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
+		}
+	}
 }
 
 EntryInfo *
@@ -821,22 +860,23 @@ load1:
 			ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
 		}
 
-		ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
+		ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_head_mutex );
 
 		/* If the LRU list has only one entry and this is it, it
 		 * doesn't need to be added again.
 		 */
 		if ( bdb->bi_cache.c_lruhead == bdb->bi_cache.c_lrutail &&
 			bdb->bi_cache.c_lruhead == *eip ) {
-			ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_mutex );
+			ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_head_mutex );
 		} else {
-
 			/* if entry is on LRU list, remove from old spot */
 			if ( (*eip)->bei_lrunext || (*eip)->bei_lruprev ) {
+				ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_tail_mutex );
 				LRU_DELETE( &bdb->bi_cache, *eip );
+				ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.lru_tail_mutex );
 			}
-			/* lru_mutex is unlocked for us */
-			bdb_cache_lru_add( bdb, locker, *eip );
+			/* lru_head_mutex is unlocked for us */
+			bdb_cache_lru_add( bdb, *eip );
 		}
 	}
 
@@ -933,10 +973,10 @@ bdb_cache_add(
 	ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
 
 	/* set lru mutex */
-	ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_mutex );
+	ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_head_mutex );
 
-	/* lru_mutex is unlocked for us */
-	bdb_cache_lru_add( bdb, locker, new );
+	/* lru_head_mutex is unlocked for us */
+	bdb_cache_lru_add( bdb, new );
 
 	return rc;
 }
@@ -1082,7 +1122,7 @@ bdb_cache_delete(
 		e->e_id, 0, 0 );
 
 	/* set lru mutex */
-	ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
+	ldap_pvt_thread_mutex_lock( &cache->lru_tail_mutex );
 
 	/* set cache write lock */
 	ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
@@ -1093,7 +1133,7 @@ bdb_cache_delete(
 	ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 	/* free lru mutex */
-	ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+	ldap_pvt_thread_mutex_unlock( &cache->lru_tail_mutex );
 
 	/* Leave entry info locked */
 
@@ -1201,7 +1241,7 @@ bdb_cache_release_all( Cache *cache )
 	/* set cache write lock */
 	ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 	/* set lru mutex */
-	ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
+	ldap_pvt_thread_mutex_lock( &cache->lru_tail_mutex );
 
 	Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_release_all\n", 0, 0, 0 );
 
@@ -1220,7 +1260,7 @@ bdb_cache_release_all( Cache *cache )
 	cache->c_dntree.bei_kids = NULL;
 
 	/* free lru mutex */
-	ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+	ldap_pvt_thread_mutex_unlock( &cache->lru_tail_mutex );
 	/* free cache write lock */
 	ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 }
diff --git a/servers/slapd/back-bdb/config.c b/servers/slapd/back-bdb/config.c
index d9f00f210f..6445e5fca9 100644
--- a/servers/slapd/back-bdb/config.c
+++ b/servers/slapd/back-bdb/config.c
@@ -55,6 +55,11 @@ static ConfigTable bdbcfg[] = {
 			"DESC 'Directory for database content' "
 			"EQUALITY caseIgnoreMatch "
 			"SYNTAX OMsDirectoryString SINGLE-VALUE )", NULL, NULL },
+	{ "cachefree", "size", 2, 2, 0, ARG_INT|ARG_OFFSET,
+		(void *)offsetof(struct bdb_info, bi_cache.c_minfree),
+		"( OLcfgDbAt:1.11 NAME 'olcDbCacheFree' "
+			"DESC 'Number of extra entries to free when max is reached' "
+			"SYNTAX OMsInteger SINGLE-VALUE )", NULL, NULL },
 	{ "cachesize", "size", 2, 2, 0, ARG_INT|ARG_OFFSET,
 		(void *)offsetof(struct bdb_info, bi_cache.c_maxsize),
 		"( OLcfgDbAt:1.1 NAME 'olcDbCacheSize' "
@@ -134,7 +139,8 @@ static ConfigOCs bdbocs[] = {
 		"MAY ( olcDbCacheSize $ olcDbCheckpoint $ olcDbConfig $ "
 		"olcDbNoSync $ olcDbDirtyRead $ olcDbIDLcacheSize $ "
 		"olcDbIndex $ olcDbLinearIndex $ olcDbLockDetect $ "
-		"olcDbMode $ olcDbSearchStack $ olcDbShmKey ) )",
+		"olcDbMode $ olcDbSearchStack $ olcDbShmKey $ "
+		" olcDbCacheFree ) )",
 		 	Cft_Database, bdbcfg },
 	{ NULL, 0, NULL }
 };
diff --git a/servers/slapd/back-bdb/delete.c b/servers/slapd/back-bdb/delete.c
index a1bef6cccd..51ff92220f 100644
--- a/servers/slapd/back-bdb/delete.c
+++ b/servers/slapd/back-bdb/delete.c
@@ -369,34 +369,53 @@ retry:	/* transaction retry */
 		goto return_results;
 	}
 
-	/* delete from id2entry */
-	rs->sr_err = bdb_id2entry_delete( op->o_bd, lt2, e );
-	if ( rs->sr_err != 0 ) {
+	/* delete indices for old attributes */
+	rs->sr_err = bdb_index_entry_del( op, lt2, e );
+	if ( rs->sr_err != LDAP_SUCCESS ) {
 		Debug(LDAP_DEBUG_TRACE,
-			"<=- " LDAP_XSTRING(bdb_delete) ": id2entry failed: "
+			"<=- " LDAP_XSTRING(bdb_delete) ": index failed: "
 			"%s (%d)\n", db_strerror(rs->sr_err), rs->sr_err, 0 );
 		switch( rs->sr_err ) {
 		case DB_LOCK_DEADLOCK:
 		case DB_LOCK_NOTGRANTED:
 			goto retry;
 		}
-		rs->sr_text = "entry delete failed";
+		rs->sr_text = "entry index delete failed";
 		rs->sr_err = LDAP_OTHER;
 		goto return_results;
 	}
 
-	/* delete indices for old attributes */
-	rs->sr_err = bdb_index_entry_del( op, lt2, e );
+	/* fixup delete CSN */
+	if ( !SLAP_SHADOW( op->o_bd )) {
+		struct berval vals[2];
+		vals[0] = op->o_csn;
+		BER_BVZERO( vals+1 );
+		rs->sr_err = bdb_index_values( op, lt2, slap_schema.si_ad_entryCSN,
+			vals, 0, SLAP_INDEX_ADD_OP );
 	if ( rs->sr_err != LDAP_SUCCESS ) {
+			switch( rs->sr_err ) {
+			case DB_LOCK_DEADLOCK:
+			case DB_LOCK_NOTGRANTED:
+				goto retry;
+			}
+			rs->sr_text = "entryCSN index update failed";
+			rs->sr_err = LDAP_OTHER;
+			goto return_results;
+		}
+	}
+
+	/* delete from id2entry */
+	rs->sr_err = bdb_id2entry_delete( op->o_bd, lt2, e );
+	if ( rs->sr_err != 0 ) {
 		Debug( LDAP_DEBUG_TRACE,
-			"<=- " LDAP_XSTRING(bdb_delete) ": index failed: "
+			"<=- " LDAP_XSTRING(bdb_delete) ": id2entry failed: "
 			"%s (%d)\n", db_strerror(rs->sr_err), rs->sr_err, 0 );
 		switch( rs->sr_err ) {
 		case DB_LOCK_DEADLOCK:
 		case DB_LOCK_NOTGRANTED:
 			goto retry;
 		}
-		rs->sr_text = "entry index delete failed";
+		rs->sr_text = "entry delete failed";
 		rs->sr_err = LDAP_OTHER;
 		goto return_results;
 	}
diff --git a/servers/slapd/back-bdb/init.c b/servers/slapd/back-bdb/init.c
index 991bbc033f..e9bbf375ac 100644
--- a/servers/slapd/back-bdb/init.c
+++ b/servers/slapd/back-bdb/init.c
@@ -69,7 +69,8 @@ bdb_db_init( BackendDB *be )
 #ifdef BDB_HIER
 	ldap_pvt_thread_mutex_init( &bdb->bi_modrdns_mutex );
 #endif
-	ldap_pvt_thread_mutex_init( &bdb->bi_cache.lru_mutex );
+	ldap_pvt_thread_mutex_init( &bdb->bi_cache.lru_head_mutex );
+	ldap_pvt_thread_mutex_init( &bdb->bi_cache.lru_tail_mutex );
 	ldap_pvt_thread_mutex_init( &bdb->bi_cache.c_dntree.bei_kids_mutex );
 	ldap_pvt_thread_rdwr_init ( &bdb->bi_cache.c_rwlock );
 	ldap_pvt_thread_rdwr_init( &bdb->bi_idl_tree_rwlock );
@@ -564,13 +565,14 @@ bdb_db_close( BackendDB *be )
 		bdb->bi_idl_lru_head = bdb->bi_idl_lru_tail = NULL;
 	}
 
-	if ( !( slapMode & SLAP_TOOL_QUICK ) && bdb->bi_dbenv ) {
-		XLOCK_ID_FREE(bdb->bi_dbenv, bdb->bi_cache.c_locker);
-		bdb->bi_cache.c_locker = 0;
-	}
-
 	/* close db environment */
 	if( bdb->bi_dbenv ) {
+		/* Free cache locker if we enabled locking */
+		if ( !( slapMode & SLAP_TOOL_QUICK )) {
+			XLOCK_ID_FREE(bdb->bi_dbenv, bdb->bi_cache.c_locker);
+			bdb->bi_cache.c_locker = 0;
+		}
+
 		/* force a checkpoint, but not if we were ReadOnly,
 		 * and not in Quick mode since there are no transactions there.
 		 */
@@ -614,7 +616,8 @@ bdb_db_destroy( BackendDB *be )
 	bdb_attr_index_destroy( bdb );
 
 	ldap_pvt_thread_rdwr_destroy ( &bdb->bi_cache.c_rwlock );
-	ldap_pvt_thread_mutex_destroy( &bdb->bi_cache.lru_mutex );
+	ldap_pvt_thread_mutex_destroy( &bdb->bi_cache.lru_head_mutex );
+	ldap_pvt_thread_mutex_destroy( &bdb->bi_cache.lru_tail_mutex );
 	ldap_pvt_thread_mutex_destroy( &bdb->bi_cache.c_dntree.bei_kids_mutex );
 #ifdef BDB_HIER
 	ldap_pvt_thread_mutex_destroy( &bdb->bi_modrdns_mutex );
@@ -653,9 +656,7 @@ bdb_back_initialize(
 
 	bi->bi_flags |=
 		SLAP_BFLAG_INCREMENT |
-#ifdef BDB_SUBENTRIES
 		SLAP_BFLAG_SUBENTRIES |
-#endif
 		SLAP_BFLAG_ALIASES |
 		SLAP_BFLAG_REFERRALS;
 
diff --git a/servers/slapd/back-bdb/modify.c b/servers/slapd/back-bdb/modify.c
index a1aeb801fc..eac9922929 100644
--- a/servers/slapd/back-bdb/modify.c
+++ b/servers/slapd/back-bdb/modify.c
@@ -91,7 +91,9 @@ int bdb_modify_internal(
 
 		switch ( mod->sm_op ) {
 		case LDAP_MOD_ADD:
-			Debug(LDAP_DEBUG_ARGS, "bdb_modify_internal: add\n", 0, 0, 0);
+			Debug(LDAP_DEBUG_ARGS,
+				"bdb_modify_internal: add %s\n",
+				mod->sm_desc->ad_cname.bv_val, 0, 0);
 			err = modify_add_values( e, mod, get_permissiveModify(op),
 				text, textbuf, textlen );
 			if( err != LDAP_SUCCESS ) {
@@ -106,7 +108,9 @@ int bdb_modify_internal(
 				break;
 			}
 
-			Debug(LDAP_DEBUG_ARGS, "bdb_modify_internal: delete\n", 0, 0, 0);
+			Debug(LDAP_DEBUG_ARGS,
+				"bdb_modify_internal: delete %s\n",
+				mod->sm_desc->ad_cname.bv_val, 0, 0);
 			err = modify_delete_values( e, mod, get_permissiveModify(op),
 				text, textbuf, textlen );
 			assert( err != LDAP_TYPE_OR_VALUE_EXISTS );
@@ -117,7 +121,9 @@ int bdb_modify_internal(
 			break;
 
 		case LDAP_MOD_REPLACE:
-			Debug(LDAP_DEBUG_ARGS, "bdb_modify_internal: replace\n", 0, 0, 0);
+			Debug(LDAP_DEBUG_ARGS,
+				"bdb_modify_internal: replace %s\n",
+				mod->sm_desc->ad_cname.bv_val, 0, 0);
 			err = modify_replace_values( e, mod, get_permissiveModify(op),
 				text, textbuf, textlen );
 			if( err != LDAP_SUCCESS ) {
@@ -128,7 +134,8 @@ int bdb_modify_internal(
 
 		case LDAP_MOD_INCREMENT:
 			Debug(LDAP_DEBUG_ARGS,
-				"bdb_modify_internal: increment\n", 0, 0, 0);
+				"bdb_modify_internal: increment %s\n",
+				mod->sm_desc->ad_cname.bv_val, 0, 0);
 			err = modify_increment_values( e, mod, get_permissiveModify(op),
 				text, textbuf, textlen );
 			if( err != LDAP_SUCCESS ) {
@@ -139,7 +146,9 @@ int bdb_modify_internal(
 			break;
 
 		case SLAP_MOD_SOFTADD:
-			Debug(LDAP_DEBUG_ARGS, "bdb_modify_internal: softadd\n", 0, 0, 0);
+			Debug(LDAP_DEBUG_ARGS,
+				"bdb_modify_internal: softadd %s\n",
+				mod->sm_desc->ad_cname.bv_val, 0, 0);
  			/* Avoid problems in index_add_mods()
  			 * We need to add index if necessary.
  			 */
diff --git a/servers/slapd/back-bdb/modrdn.c b/servers/slapd/back-bdb/modrdn.c
index 422420dcaf..6a25d2882d 100644
--- a/servers/slapd/back-bdb/modrdn.c
+++ b/servers/slapd/back-bdb/modrdn.c
@@ -796,22 +796,13 @@ done:
 	if ( new_rdn != NULL ) {
 		ldap_rdnfree_x( new_rdn, op->o_tmpmemctx );
 	}
+
 	if ( old_rdn != NULL ) {
 		ldap_rdnfree_x( old_rdn, op->o_tmpmemctx );
 	}
+
 	if( mod != NULL ) {
-		Modifications *tmp;
-		for (; mod; mod=tmp ) {
-			tmp = mod->sml_next;
-			/* slap_modrdn2mods does things one way,
-			 * slap_mods_opattrs does it differently
-			 */
-			if ( mod->sml_op != SLAP_MOD_SOFTADD &&
-				mod->sml_op != LDAP_MOD_DELETE ) break;
-			if ( mod->sml_nvalues ) free( mod->sml_nvalues[0].bv_val );
-			free( mod );
-		}
-		slap_mods_free( mod, 1 );
+		slap_modrdn2mods_free( mod );
 	}
 
 	/* LDAP v3 Support */
diff --git a/servers/slapd/back-bdb/search.c b/servers/slapd/back-bdb/search.c
index e39c23daf9..df70a4357a 100644
--- a/servers/slapd/back-bdb/search.c
+++ b/servers/slapd/back-bdb/search.c
@@ -465,7 +465,7 @@ dn2entry_retry:
 #endif
 			rs->sr_ref = referral_rewrite( default_referral,
 				NULL, &op->o_req_dn, op->oq_search.rs_scope );
-			rs->sr_err = LDAP_REFERRAL;
+			rs->sr_err = rs->sr_ref != NULL ? LDAP_REFERRAL : LDAP_NO_SUCH_OBJECT;
 		}
 
 		send_ldap_result( op, rs );
@@ -726,28 +726,24 @@ fetch_entry_retry:
 
 		rs->sr_entry = e;
 
-#ifdef BDB_SUBENTRIES
-		{
-			if ( is_entry_subentry( e ) ) {
-				if( op->oq_search.rs_scope != LDAP_SCOPE_BASE ) {
-					if(!get_subentries_visibility( op )) {
-						/* only subentries are visible */
-						goto loop_continue;
-					}
-
-				} else if ( get_subentries( op ) &&
-					!get_subentries_visibility( op ))
-				{
+		if ( is_entry_subentry( e ) ) {
+			if( op->oq_search.rs_scope != LDAP_SCOPE_BASE ) {
+				if(!get_subentries_visibility( op )) {
 					/* only subentries are visible */
 					goto loop_continue;
 				}
 
-			} else if ( get_subentries_visibility( op )) {
+			} else if ( get_subentries( op ) &&
+				!get_subentries_visibility( op ))
+			{
 				/* only subentries are visible */
 				goto loop_continue;
 			}
+
+		} else if ( get_subentries_visibility( op )) {
+			/* only subentries are visible */
+			goto loop_continue;
 		}
-#endif /* BDB_SUBENTRIES */
 
 		/* Does this candidate actually satisfy the search scope?
 		 *
@@ -1051,13 +1047,11 @@ static int search_candidates(
 #else
 	AttributeAssertion aa_ref = { NULL, BER_BVNULL };
 #endif
-#ifdef BDB_SUBENTRIES
 	Filter	sf;
 #ifdef LDAP_COMP_MATCH
 	AttributeAssertion aa_subentry = { NULL, BER_BVNULL, NULL };
 #else
 	AttributeAssertion aa_subentry = { NULL, BER_BVNULL };
-#endif
 #endif
 
 	/*
@@ -1104,7 +1098,6 @@ static int search_candidates(
 	/* Filter depth increased again, adding dummy clause */
 	depth++;
 
-#ifdef BDB_SUBENTRIES
 	if( get_subentries_visibility( op ) ) {
 		struct berval bv_subentry = BER_BVC( "subentry" );
 		sf.f_choice = LDAP_FILTER_EQUALITY;
@@ -1114,7 +1107,6 @@ static int search_candidates(
 		sf.f_next = nf.f_next;
 		nf.f_next = &sf;
 	}
-#endif
 
 	/* Allocate IDL stack, plus 1 more for former tmp */
 	if ( depth+1 > bdb->bi_search_stack_depth ) {
diff --git a/servers/slapd/back-bdb/tools.c b/servers/slapd/back-bdb/tools.c
index 9c97048485..91b5226474 100644
--- a/servers/slapd/back-bdb/tools.c
+++ b/servers/slapd/back-bdb/tools.c
@@ -483,11 +483,11 @@ ID bdb_tool_entry_put(
 		goto done;
 	}
 
-	/* id2entry index */
-	rc = bdb_id2entry_add( be, tid, e );
+	if ( !bdb->bi_linear_index )
+		rc = bdb_tool_index_add( &op, tid, e );
 	if( rc != 0 ) {
 		snprintf( text->bv_val, text->bv_len,
-				"id2entry_add failed: %s (%d)",
+				"index_entry_add failed: %s (%d)",
 				db_strerror(rc), rc );
 		Debug( LDAP_DEBUG_ANY,
 			"=> " LDAP_XSTRING(bdb_tool_entry_put) ": %s\n",
@@ -495,11 +495,11 @@ ID bdb_tool_entry_put(
 		goto done;
 	}
 
-	if ( !bdb->bi_linear_index )
-		rc = bdb_tool_index_add( &op, tid, e );
+	/* id2entry index */
+	rc = bdb_id2entry_add( be, tid, e );
 	if( rc != 0 ) {
 		snprintf( text->bv_val, text->bv_len,
-				"index_entry_add failed: %s (%d)",
+				"id2entry_add failed: %s (%d)",
 				db_strerror(rc), rc );
 		Debug( LDAP_DEBUG_ANY,
 			"=> " LDAP_XSTRING(bdb_tool_entry_put) ": %s\n",
@@ -688,33 +688,6 @@ ID bdb_tool_entry_modify(
 		goto done;
 	}
 
-#if 0
-	/* FIXME: this is bogus, we don't have the old values to delete
-	 * from the index because the given entry has already been modified.
-	 */
-	rc = bdb_index_entry_del( &op, tid, e );
-	if( rc != 0 ) {
-		snprintf( text->bv_val, text->bv_len,
-				"index_entry_del failed: %s (%d)",
-				db_strerror(rc), rc );
-		Debug( LDAP_DEBUG_ANY,
-			"=> " LDAP_XSTRING(bdb_tool_entry_modify) ": %s\n",
-			text->bv_val, 0, 0 );
-		goto done;
-	}
-#endif
-
-	rc = bdb_index_entry_add( &op, tid, e );
-	if( rc != 0 ) {
-		snprintf( text->bv_val, text->bv_len,
-				"index_entry_add failed: %s (%d)",
-				db_strerror(rc), rc );
-		Debug( LDAP_DEBUG_ANY,
-			"=> " LDAP_XSTRING(bdb_tool_entry_modify) ": %s\n",
-			text->bv_val, 0, 0 );
-		goto done;
-	}
-
 done:
 	if( rc == 0 ) {
 		if (! (slapMode & SLAP_TOOL_QUICK)) {
diff --git a/servers/slapd/modrdn.c b/servers/slapd/modrdn.c
index e455d71a8a..39165a37b0 100644
--- a/servers/slapd/modrdn.c
+++ b/servers/slapd/modrdn.c
@@ -291,7 +291,7 @@ fe_op_modrdn( Operation *op, SlapReply *rs )
 		int repl_user = be_isupdate( op );
 #ifndef SLAPD_MULTIMASTER
 		if ( !SLAP_SHADOW(op->o_bd) || repl_user )
-#endif
+#endif /* ! SLAPD_MULTIMASTER */
 		{
 			slap_callback cb = { NULL, slap_replog_cb, NULL, NULL };
 
@@ -299,7 +299,7 @@ fe_op_modrdn( Operation *op, SlapReply *rs )
 
 #ifdef SLAPD_MULTIMASTER
 			if ( !op->o_bd->be_update_ndn.bv_len || !repl_user )
-#endif
+#endif /* SLAPD_MULTIMASTER */
 			{
 				cb.sc_next = op->o_callback;
 				op->o_callback = &cb;
@@ -363,7 +363,7 @@ fe_op_modrdn( Operation *op, SlapReply *rs )
 				send_ldap_error( op, rs, LDAP_UNWILLING_TO_PERFORM,
 					"shadow context; no update referral" );
 			}
-#endif
+#endif /* ! SLAPD_MULTIMASTER */
 		}
 	} else {
 		send_ldap_error( op, rs, LDAP_UNWILLING_TO_PERFORM,
@@ -519,3 +519,30 @@ done:
 
 	return rs->sr_err;
 }
+
+void
+slap_modrdn2mods_free( Modifications *mod )
+{
+	Modifications *tmp;
+
+	for ( ; mod; mod = tmp ) {
+		tmp = mod->sml_next;
+		/* slap_modrdn2mods does things one way,
+		 * slap_mods_opattrs does it differently
+		 */
+		if ( mod->sml_op != SLAP_MOD_SOFTADD &&
+			mod->sml_op != LDAP_MOD_DELETE )
+		{
+			break;
+		}
+
+		if ( mod->sml_nvalues ) {
+			free( mod->sml_nvalues[0].bv_val );
+		}
+
+		free( mod );
+	}
+
+	slap_mods_free( mod, 1 );
+}
+
diff --git a/servers/slapd/proto-slap.h b/servers/slapd/proto-slap.h
index fee6bf4547..80111489fe 100644
--- a/servers/slapd/proto-slap.h
+++ b/servers/slapd/proto-slap.h
@@ -1016,13 +1016,15 @@ LDAP_SLAPD_F (int) filter_matched_values(
 /*
  * modrdn.c
  */
-LDAP_SLAPD_F (int) slap_modrdn2mods(
+LDAP_SLAPD_F (int) slap_modrdn2mods LDAP_P((
 	Operation	*op,
 	SlapReply	*rs,
 	Entry		*e,
 	LDAPRDN		oldrdn,
 	LDAPRDN		newrdn,
-	Modifications	**pmod );
+	Modifications	**pmod ));
+
+LDAP_SLAPD_F (void) slap_modrdn2mods_free LDAP_P(( Modifications *mod ));
 
 /*
  * modify.c
-- 
2.39.5