X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;ds=inline;f=servers%2Fslapd%2Fback-bdb%2Fcache.c;h=260623cfa82ff4bef803c33abf572885b67e5ff1;hb=0121f8c01dcdef0827c8e6a1770d0a5ae3b0806e;hp=7cd7194ab7c407b04b7a27c5d338eb72e729de51;hpb=3640a6f7e55bb724cc8ce09409617f5eae88bc52;p=openldap

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index 7cd7194ab7..260623cfa8 100644
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -2,7 +2,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2007 The OpenLDAP Foundation.
+ * Copyright 2000-2009 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -155,17 +155,11 @@ bdb_cache_lru_link( struct bdb_info *bdb, EntryInfo *ei )
  * alternatives though.
  */
 
-#if DB_VERSION_FULL >= 0x04060012
-#define BDB_LOCKID(locker)	locker->id
-#else
-#define BDB_LOCKID(locker)	locker
-#endif
-
 /* Atomically release and reacquire a lock */
 int
 bdb_cache_entry_db_relock(
 	struct bdb_info *bdb,
-	BDB_LOCKER locker,
+	DB_TXN *txn,
 	EntryInfo *ei,
 	int rw,
 	int tryOnly,
@@ -189,7 +183,7 @@ bdb_cache_entry_db_relock(
 	list[1].lock = *lock;
 	list[1].mode = rw ? DB_LOCK_WRITE : DB_LOCK_READ;
 	list[1].obj = &lockobj;
-	rc = bdb->bi_dbenv->lock_vec(bdb->bi_dbenv, BDB_LOCKID(locker), tryOnly ? DB_LOCK_NOWAIT : 0,
+	rc = bdb->bi_dbenv->lock_vec(bdb->bi_dbenv, TXN_ID(txn), tryOnly ? DB_LOCK_NOWAIT : 0,
 		list, 2, NULL );
 
 	if (rc && !tryOnly) {
@@ -204,7 +198,7 @@ bdb_cache_entry_db_relock(
 }
 
 static int
-bdb_cache_entry_db_lock( struct bdb_info *bdb, BDB_LOCKER locker, EntryInfo *ei,
+bdb_cache_entry_db_lock( struct bdb_info *bdb, DB_TXN *txn, EntryInfo *ei,
 	int rw, int tryOnly, DB_LOCK *lock )
 {
 #ifdef NO_DB_LOCK
@@ -224,7 +218,7 @@ bdb_cache_entry_db_lock( struct bdb_info *bdb, BDB_LOCKER locker, EntryInfo *ei,
 	lockobj.data = &ei->bei_id;
 	lockobj.size = sizeof(ei->bei_id) + 1;
 
-	rc = LOCK_GET(bdb->bi_dbenv, BDB_LOCKID(locker), tryOnly ? DB_LOCK_NOWAIT : 0,
+	rc = LOCK_GET(bdb->bi_dbenv, TXN_ID(txn), tryOnly ? DB_LOCK_NOWAIT : 0,
 					&lockobj, db_rw, lock);
 	if (rc && !tryOnly) {
 		Debug( LDAP_DEBUG_TRACE,
@@ -257,15 +251,28 @@ bdb_cache_return_entry_rw( struct bdb_info *bdb, Entry *e,
 	EntryInfo *ei;
 	int free = 0;
 
-	bdb_cache_entry_db_unlock( bdb, lock );
 	ei = e->e_private;
-	bdb_cache_entryinfo_lock( ei );
-	if ( ei->bei_state & CACHE_ENTRY_NOT_CACHED ) {
-		ei->bei_e = NULL;
-		ei->bei_state ^= CACHE_ENTRY_NOT_CACHED;
-		free = 1;
+	if ( ei &&
+		( ei->bei_state & CACHE_ENTRY_NOT_CACHED ) &&
+		( bdb_cache_entryinfo_trylock( ei ) == 0 )) {
+		if ( ei->bei_state & CACHE_ENTRY_NOT_CACHED ) {
+			/* Releasing the entry can only be done when
+			 * we know that nobody else is using it, i.e we
+			 * should have an entry_db writelock.  But the
+			 * flag is only set by the thread that loads the
+			 * entry, and only if no other threads has found
+			 * it while it was working.  All other threads
+			 * clear the flag, which mean that we should be
+			 * the only thread using the entry if the flag
+			 * is set here.
+			 */
+			ei->bei_e = NULL;
+			ei->bei_state ^= CACHE_ENTRY_NOT_CACHED;
+			free = 1;
+		}
+		bdb_cache_entryinfo_unlock( ei );
 	}
-	bdb_cache_entryinfo_unlock( ei );
+	bdb_cache_entry_db_unlock( bdb, lock );
 	if ( free ) {
 		e->e_private = NULL;
 		bdb_entry_return( e );
@@ -351,6 +358,8 @@ bdb_entryinfo_add_internal(
 		ei->bei_rdn.bv_val = NULL;
 #endif
 	} else {
+		int rc;
+
 		bdb->bi_cache.c_eiused++;
 		ber_dupbv( &ei2->bei_nrdn, &ei->bei_nrdn );
 
@@ -360,8 +369,13 @@ bdb_entryinfo_add_internal(
 		 */
 		if ( ei->bei_parent->bei_kids || !ei->bei_parent->bei_id )
 			bdb->bi_cache.c_leaves++;
-		avl_insert( &ei->bei_parent->bei_kids, ei2, bdb_rdn_cmp,
+		rc = avl_insert( &ei->bei_parent->bei_kids, ei2, bdb_rdn_cmp,
 			avl_dup_error );
+		if ( rc ) {
+			/* This should never happen; entry cache is corrupt */
+			bdb->bi_dbenv->log_flush( bdb->bi_dbenv, NULL );
+			assert( !rc );
+		}
 #ifdef BDB_HIER
 		ei->bei_parent->bei_ckids++;
 #endif
@@ -418,6 +432,7 @@ bdb_cache_find_ndn(
 		ei.bei_parent = eip;
 		ei2 = (EntryInfo *)avl_find( eip->bei_kids, &ei, bdb_rdn_cmp );
 		if ( !ei2 ) {
+			DB_LOCK lock;
 			int len = ei.bei_nrdn.bv_len;
 				
 			if ( BER_BVISEMPTY( ndn )) {
@@ -429,18 +444,27 @@ bdb_cache_find_ndn(
 				(ei.bei_nrdn.bv_val - ndn->bv_val);
 			bdb_cache_entryinfo_unlock( eip );
 
-			rc = bdb_dn2id( op, txn, &ei.bei_nrdn, &ei );
+			BDB_LOG_PRINTF( bdb->bi_dbenv, NULL, "slapd Reading %s",
+				ei.bei_nrdn.bv_val );
+
+			lock.mode = DB_LOCK_NG;
+			rc = bdb_dn2id( op, &ei.bei_nrdn, &ei, txn, &lock );
 			if (rc) {
 				bdb_cache_entryinfo_lock( eip );
+				bdb_cache_entry_db_unlock( bdb, &lock );
 				*res = eip;
 				return rc;
 			}
 
+			BDB_LOG_PRINTF( bdb->bi_dbenv, NULL, "slapd Read got %s(%d)",
+				ei.bei_nrdn.bv_val, ei.bei_id );
+
 			/* DN exists but needs to be added to cache */
 			ei.bei_nrdn.bv_len = len;
 			rc = bdb_entryinfo_add_internal( bdb, &ei, &ei2 );
 			/* add_internal left eip and c_rwlock locked */
 			ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+			bdb_cache_entry_db_unlock( bdb, &lock );
 			if ( rc ) {
 				*res = eip;
 				return rc;
@@ -484,8 +508,7 @@ bdb_cache_find_ndn(
 int
 hdb_cache_find_parent(
 	Operation *op,
-	DB_TXN *txn,
-	BDB_LOCKER	locker,
+	DB_TXN	*txn,
 	ID id,
 	EntryInfo **res )
 {
@@ -498,7 +521,7 @@ hdb_cache_find_parent(
 	ei.bei_ckids = 0;
 
 	for (;;) {
-		rc = hdb_dn2id_parent( op, txn, locker, &ei, &eip.bei_id );
+		rc = hdb_dn2id_parent( op, txn, &ei, &eip.bei_id );
 		if ( rc ) break;
 
 		/* Save the previous node, if any */
@@ -635,31 +658,48 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
 	DB_LOCK		lock, *lockp;
 	EntryInfo *elru, *elnext = NULL;
 	int count, islocked, eimax;
+	int efree = 0, eifree = 0, eicount, ecount;
+#ifdef LDAP_DEBUG
+	int iter;
+#endif
 
 	/* Wait for the mutex; we're the only one trying to purge. */
 	ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_lru_mutex );
 
-	if ( bdb->bi_cache.c_cursize <= bdb->bi_cache.c_maxsize ) {
+	/* maximum number of EntryInfo leaves to cache. In slapcat
+	 * we always free all leaf nodes.
+	 */
+	if ( slapMode & SLAP_TOOL_READONLY )
+		eimax = 0;
+	else
+		eimax = bdb->bi_cache.c_eimax;
+
+	if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize )
+		efree = bdb->bi_cache.c_minfree;
+	if ( bdb->bi_cache.c_leaves > eimax ) {
+		eifree = bdb->bi_cache.c_minfree * 10;
+		if ( eifree >= eimax )
+			eifree = eimax / 2;
+	}
+
+	if ( !efree && !eifree ) {
 		ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
 		bdb->bi_cache.c_purging = 0;
 		return;
 	}
 
-	if ( bdb->bi_cache.c_locker ) {
+	if ( bdb->bi_cache.c_txn ) {
 		lockp = &lock;
 	} else {
 		lockp = NULL;
 	}
 
 	count = 0;
-
-	/* maximum number of EntryInfo leaves to cache. In slapcat
-	 * we always free all leaf nodes.
-	 */
-	if ( slapMode & SLAP_TOOL_READONLY )
-		eimax = 0;
-	else
-		eimax = bdb->bi_cache.c_eimax;
+	eicount = 0;
+	ecount = 0;
+#ifdef LDAP_DEBUG
+	iter = 0;
+#endif
 
 	/* Look for an unused entry to remove */
 	for ( elru = bdb->bi_cache.c_lruhead; elru; elru = elnext ) {
@@ -692,18 +732,32 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
 		 * the object is idle.
 		 */
 		if ( bdb_cache_entry_db_lock( bdb,
-			bdb->bi_cache.c_locker, elru, 1, 1, lockp ) == 0 ) {
+			bdb->bi_cache.c_txn, elru, 1, 1, lockp ) == 0 ) {
 
 			/* Free entry for this node if it's present */
 			if ( elru->bei_e ) {
-				elru->bei_e->e_private = NULL;
+				ecount++;
+
+				/* the cache may have gone over the limit while we
+				 * weren't looking, so double check.
+				 */
+				if ( !efree && ecount > bdb->bi_cache.c_maxsize )
+					efree = bdb->bi_cache.c_minfree;
+
+				if ( count < efree ) {
+					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;
-				count++;
+					elru->bei_e = NULL;
+					count++;
+				} else {
+					/* Keep this node cached, skip to next */
+					bdb_cache_entry_db_unlock( bdb, lockp );
+					goto next;
+				}
 			}
 			bdb_cache_entry_db_unlock( bdb, lockp );
 
@@ -713,26 +767,36 @@ bdb_cache_lru_purge( struct bdb_info *bdb )
 			if ( elru->bei_kids ) {
 				/* Drop from list, we ignore it... */
 				LRU_DEL( &bdb->bi_cache, elru );
-			} else if ( bdb->bi_cache.c_leaves > eimax ) {
+			} else if ( eicount < eifree ) {
 				/* Too many leaf nodes, free this one */
 				bdb_cache_delete_internal( &bdb->bi_cache, elru, 0 );
 				bdb_cache_delete_cleanup( &bdb->bi_cache, elru );
 				islocked = 0;
+				eicount++;
 			}	/* Leave on list until we need to free it */
 		}
 
+next:
 		if ( islocked )
 			bdb_cache_entryinfo_unlock( elru );
 
-		if ( count >= bdb->bi_cache.c_minfree ) {
-			ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
-			bdb->bi_cache.c_cursize -= count;
-			ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
+		if ( count >= efree && eicount >= eifree ) {
+			if ( count || ecount > bdb->bi_cache.c_cursize ) {
+				ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
+				/* HACK: we seem to be losing track, fix up now */
+				if ( ecount > bdb->bi_cache.c_cursize )
+					bdb->bi_cache.c_cursize = ecount;
+				bdb->bi_cache.c_cursize -= count;
+				ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
+			}
 			break;
 		}
 bottom:
 		if ( elnext == bdb->bi_cache.c_lruhead )
 			break;
+#ifdef LDAP_DEBUG
+		iter++;
+#endif
 	}
 
 	bdb->bi_cache.c_lruhead = elnext;
@@ -770,7 +834,6 @@ bdb_cache_find_id(
 	ID				id,
 	EntryInfo	**eip,
 	int		flag,
-	BDB_LOCKER	locker,
 	DB_LOCK		*lock )
 {
 	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
@@ -819,7 +882,7 @@ again:	ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
 	/* See if the ID exists in the database; add it to the cache if so */
 	if ( !*eip ) {
 #ifndef BDB_HIER
-		rc = bdb_id2entry( op->o_bd, tid, locker, id, &ep );
+		rc = bdb_id2entry( op->o_bd, tid, id, &ep );
 		if ( rc == 0 ) {
 			rc = bdb_cache_find_ndn( op, tid,
 				&ep->e_nname, eip );
@@ -835,13 +898,18 @@ again:	ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
 			}
 		}
 #else
-		rc = hdb_cache_find_parent(op, tid, locker, id, eip );
+		rc = hdb_cache_find_parent(op, tid, id, eip );
 		if ( rc == 0 ) flag |= ID_LOCKED;
 #endif
 	}
 
 	/* Ok, we found the info, do we have the entry? */
 	if ( rc == 0 ) {
+		if ( !( flag & ID_LOCKED )) {
+			bdb_cache_entryinfo_lock( *eip );
+			flag |= ID_LOCKED;
+		}
+
 		if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
 			rc = DB_NOTFOUND;
 		} else {
@@ -861,27 +929,29 @@ load1:
 				(*eip)->bei_state |= CACHE_ENTRY_LOADING;
 			}
 
-			/* If the entry was loaded before but uncached, and we need
-			 * it again, clear the uncached state
-			 */
-			if ( (*eip)->bei_state & CACHE_ENTRY_NOT_CACHED ) {
-				(*eip)->bei_state ^= CACHE_ENTRY_NOT_CACHED;
-				if ( flag & ID_NOCACHE )
-					flag ^= ID_NOCACHE;
+			if ( !load ) {
+				/* Clear the uncached state if we are not
+				 * loading it, i.e it is already cached or
+				 * another thread is currently loading it.
+				 */
+				if ( (*eip)->bei_state & CACHE_ENTRY_NOT_CACHED ) {
+					(*eip)->bei_state &= ~CACHE_ENTRY_NOT_CACHED;
+				}
+				flag &= ~ID_NOCACHE;
 			}
 
 			if ( flag & ID_LOCKED ) {
 				bdb_cache_entryinfo_unlock( *eip );
 				flag ^= ID_LOCKED;
 			}
-			rc = bdb_cache_entry_db_lock( bdb, locker, *eip, load, 0, lock );
+			rc = bdb_cache_entry_db_lock( bdb, tid, *eip, load, 0, lock );
 			if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
 				rc = DB_NOTFOUND;
 				bdb_cache_entry_db_unlock( bdb, lock );
 			} else if ( rc == 0 ) {
 				if ( load ) {
 					if ( !ep) {
-						rc = bdb_id2entry( op->o_bd, tid, locker, id, &ep );
+						rc = bdb_id2entry( op->o_bd, tid, id, &ep );
 					}
 					if ( rc == 0 ) {
 						ep->e_private = *eip;
@@ -894,15 +964,19 @@ load1:
 #endif
 						ep = NULL;
 						bdb_cache_lru_link( bdb, *eip );
-						if ( flag & ID_NOCACHE ) {
-							bdb_cache_entryinfo_lock( *eip );
-							(*eip)->bei_state |= CACHE_ENTRY_NOT_CACHED;
+						if (( flag & ID_NOCACHE ) &&
+							( bdb_cache_entryinfo_trylock( *eip ) == 0 )) {
+							/* Set the cached state only if no other thread
+							 * found the info while we were loading the entry.
+							 */
+							if ( (*eip)->bei_finders == 1 )
+								(*eip)->bei_state |= CACHE_ENTRY_NOT_CACHED;
 							bdb_cache_entryinfo_unlock( *eip );
 						}
 					}
 					if ( rc == 0 ) {
 						/* If we succeeded, downgrade back to a readlock. */
-						rc = bdb_cache_entry_db_relock( bdb, locker,
+						rc = bdb_cache_entry_db_relock( bdb, tid,
 							*eip, 0, 0, lock );
 					} else {
 						/* Otherwise, release the lock. */
@@ -923,21 +997,21 @@ load1:
 					rc = bdb_fix_dn( (*eip)->bei_e, 1 );
 					if ( rc ) {
 						bdb_cache_entry_db_relock( bdb,
-							locker, *eip, 1, 0, lock );
+							tid, *eip, 1, 0, lock );
 						/* check again in case other modifier did it already */
 						if ( bdb_fix_dn( (*eip)->bei_e, 1 ) )
 							rc = bdb_fix_dn( (*eip)->bei_e, 2 );
 						bdb_cache_entry_db_relock( bdb,
-							locker, *eip, 0, 0, lock );
+							tid, *eip, 0, 0, lock );
 					}
 #endif
 				}
-				bdb_cache_entryinfo_lock( *eip );
-				(*eip)->bei_finders--;
-				if ( load )
-					(*eip)->bei_state ^= CACHE_ENTRY_LOADING;
-				bdb_cache_entryinfo_unlock( *eip );
 			}
+			bdb_cache_entryinfo_lock( *eip );
+			(*eip)->bei_finders--;
+			if ( load )
+				(*eip)->bei_state ^= CACHE_ENTRY_LOADING;
+			bdb_cache_entryinfo_unlock( *eip );
 		}
 	}
 	if ( flag & ID_LOCKED ) {
@@ -954,17 +1028,22 @@ load1:
 	if ( rc == 0 ) {
 		int purge = 0;
 
-		if ( load ) {
-			if ( !( flag & ID_NOCACHE )) {
-				ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
-				bdb->bi_cache.c_cursize++;
-				if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize &&
-					!bdb->bi_cache.c_purging ) {
+		if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ||
+			bdb->bi_cache.c_leaves > bdb->bi_cache.c_eimax ) {
+			ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
+			if ( !bdb->bi_cache.c_purging ) {
+				if ( !( flag & ID_NOCACHE )) {
+					bdb->bi_cache.c_cursize++;
+					if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
+						purge = 1;
+						bdb->bi_cache.c_purging = 1;
+					}
+				} else if ( bdb->bi_cache.c_leaves > bdb->bi_cache.c_eimax ) {
 					purge = 1;
 					bdb->bi_cache.c_purging = 1;
 				}
-				ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
 			}
+			ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
 		}
 		if ( purge )
 			bdb_cache_lru_purge( bdb );
@@ -1007,7 +1086,7 @@ bdb_cache_add(
 	EntryInfo *eip,
 	Entry *e,
 	struct berval *nrdn,
-	BDB_LOCKER locker,
+	DB_TXN *txn,
 	DB_LOCK *lock )
 {
 	EntryInfo *new, ei;
@@ -1024,7 +1103,7 @@ bdb_cache_add(
 	/* Lock this entry so that bdb_add can run to completion.
 	 * It can only fail if BDB has run out of lock resources.
 	 */
-	rc = bdb_cache_entry_db_lock( bdb, locker, &ei, 0, 0, lock );
+	rc = bdb_cache_entry_db_lock( bdb, txn, &ei, 0, 0, lock );
 	if ( rc ) {
 		bdb_cache_entryinfo_unlock( eip );
 		return rc;
@@ -1082,13 +1161,13 @@ bdb_cache_modify(
 	struct bdb_info *bdb,
 	Entry *e,
 	Attribute *newAttrs,
-	BDB_LOCKER locker,
+	DB_TXN *txn,
 	DB_LOCK *lock )
 {
 	EntryInfo *ei = BEI(e);
 	int rc;
 	/* Get write lock on data */
-	rc = bdb_cache_entry_db_relock( bdb, locker, ei, 1, 0, lock );
+	rc = bdb_cache_entry_db_relock( bdb, txn, ei, 1, 0, lock );
 
 	/* If we've done repeated mods on a cached entry, then e_attrs
 	 * is no longer contiguous with the entry, and must be freed.
@@ -1112,7 +1191,7 @@ bdb_cache_modrdn(
 	struct berval *nrdn,
 	Entry *new,
 	EntryInfo *ein,
-	BDB_LOCKER locker,
+	DB_TXN *txn,
 	DB_LOCK *lock )
 {
 	EntryInfo *ei = BEI(e), *pei;
@@ -1122,7 +1201,7 @@ bdb_cache_modrdn(
 #endif
 
 	/* Get write lock on data */
-	rc =  bdb_cache_entry_db_relock( bdb, locker, ei, 1, 0, lock );
+	rc =  bdb_cache_entry_db_relock( bdb, txn, ei, 1, 0, lock );
 	if ( rc ) return rc;
 
 	/* If we've done repeated mods on a cached entry, then e_attrs
@@ -1217,7 +1296,7 @@ int
 bdb_cache_delete(
 	struct bdb_info *bdb,
     Entry		*e,
-    BDB_LOCKER	locker,
+    DB_TXN *txn,
     DB_LOCK	*lock )
 {
 	EntryInfo *ei = BEI(e);
@@ -1225,18 +1304,19 @@ bdb_cache_delete(
 
 	assert( e->e_private != NULL );
 
+	/* Lock the entry's info */
+	bdb_cache_entryinfo_lock( ei );
+
 	/* Set this early, warn off any queriers */
 	ei->bei_state |= CACHE_ENTRY_DELETED;
 
-	/* Lock the entry's info */
-	bdb_cache_entryinfo_lock( ei );
+	bdb_cache_entryinfo_unlock( ei );
 
 	/* Get write lock on the data */
-	rc = bdb_cache_entry_db_relock( bdb, locker, ei, 1, 0, lock );
+	rc = bdb_cache_entry_db_relock( bdb, txn, ei, 1, 0, lock );
 	if ( rc ) {
 		/* couldn't lock, undo and give up */
 		ei->bei_state ^= CACHE_ENTRY_DELETED;
-		bdb_cache_entryinfo_unlock( ei );
 		return rc;
 	}
 
@@ -1251,8 +1331,6 @@ bdb_cache_delete(
 	/* free lru mutex */
 	ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
 
-	/* Leave entry info locked */
-
 	return( rc );
 }
 
@@ -1261,6 +1339,8 @@ bdb_cache_delete_cleanup(
 	Cache *cache,
 	EntryInfo *ei )
 {
+	/* Enter with ei locked */
+
 	if ( ei->bei_e ) {
 		ei->bei_e->e_private = NULL;
 #ifdef SLAP_ZONE_ALLOC
@@ -1403,56 +1483,36 @@ bdb_lru_print( Cache *cache )
 #endif
 #endif
 
-#ifdef BDB_REUSE_LOCKERS
 static void
-bdb_locker_id_free( void *key, void *data )
+bdb_reader_free( void *key, void *data )
 {
-	DB_ENV *env = key;
-	u_int32_t lockid;
-	int rc;
+	/* DB_ENV *env = key; */
+	DB_TXN *txn = data;
 
-#if DB_VERSION_FULL >= 0x04060012
-	BDB_LOCKER lptr = data;
-	lockid = lptr->id;
-#else
-	lockid = (long)data;
-#endif
-	rc = XLOCK_ID_FREE( env, lockid );
-	if ( rc == EINVAL ) {
-		DB_LOCKREQ lr;
-		Debug( LDAP_DEBUG_ANY,
-			"bdb_locker_id_free: %lu err %s(%d)\n",
-			(unsigned long) lockid, db_strerror(rc), rc );
-		/* release all locks held by this locker. */
-		lr.op = DB_LOCK_PUT_ALL;
-		lr.obj = NULL;
-		env->lock_vec( env, lockid, 0, &lr, 1, NULL );
-		XLOCK_ID_FREE( env, lockid );
-	}
+	if ( txn ) TXN_ABORT( txn );
 }
 
 /* free up any keys used by the main thread */
 void
-bdb_locker_flush( DB_ENV *env )
+bdb_reader_flush( DB_ENV *env )
 {
 	void *data;
 	void *ctx = ldap_pvt_thread_pool_context();
 
 	if ( !ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
-		ldap_pvt_thread_pool_setkey( ctx, env, NULL, NULL );
-		bdb_locker_id_free( env, data );
+		ldap_pvt_thread_pool_setkey( ctx, env, NULL, 0, NULL, NULL );
+		bdb_reader_free( env, data );
 	}
 }
 
 int
-bdb_locker_id( Operation *op, DB_ENV *env, BDB_LOCKER *locker )
+bdb_reader_get( Operation *op, DB_ENV *env, DB_TXN **txn )
 {
 	int i, rc;
-	u_int32_t lockid;
 	void *data;
 	void *ctx;
 
-	if ( !env || !locker ) return -1;
+	if ( !env || !txn ) return -1;
 
 	/* If no op was provided, try to find the ctx anyway... */
 	if ( op ) {
@@ -1463,42 +1523,29 @@ bdb_locker_id( Operation *op, DB_ENV *env, BDB_LOCKER *locker )
 
 	/* Shouldn't happen unless we're single-threaded */
 	if ( !ctx ) {
-		*locker = 0;
+		*txn = NULL;
 		return 0;
 	}
 
 	if ( ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
 		for ( i=0, rc=1; rc != 0 && i<4; i++ ) {
-			rc = XLOCK_ID( env, &lockid );
+			rc = TXN_BEGIN( env, NULL, txn, DB_READ_COMMITTED );
 			if (rc) ldap_pvt_thread_yield();
 		}
 		if ( rc != 0) {
 			return rc;
 		}
-#if DB_VERSION_FULL >= 0x04060012
-		{ BDB_LOCKER lptr;
-		__lock_getlocker( env->lk_handle, lockid, 0, &lptr );
-		data = lptr;
-		}
-#else
-		data = (void *)((long)lockid);
-#endif
+		data = *txn;
 		if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, env,
-			data, bdb_locker_id_free ) ) ) {
-			XLOCK_ID_FREE( env, lockid );
-			Debug( LDAP_DEBUG_ANY, "bdb_locker_id: err %s(%d)\n",
+			data, bdb_reader_free, NULL, NULL ) ) ) {
+			TXN_ABORT( *txn );
+			Debug( LDAP_DEBUG_ANY, "bdb_reader_get: err %s(%d)\n",
 				db_strerror(rc), rc, 0 );
 
 			return rc;
 		}
 	} else {
-		lockid = (long)data;
+		*txn = data;
 	}
-#if DB_VERSION_FULL >= 0x04060012
-	*locker = data;
-#else
-	*locker = lockid;
-#endif
 	return 0;
 }
-#endif /* BDB_REUSE_LOCKERS */