Entry must be locked before adding it to the cache.

This removes a race condition upon the entry.

servers/slapd/back-ldbm/add.c

@@ -123,13 +123,34 @@ ldbm_back_add(
 		pthread_mutex_unlock(&li->li_add_mutex);
 	}
 
+	/* acquire required reader/writer lock */
+	if (entry_rdwr_lock(e, 1)) {
+		if( p != NULL) {
+			/* free parent and writer lock */
+			cache_return_entry_w( &li->li_cache, p ); 
+		}
+
+		if ( rootlock ) {
+			/* release root lock */
+			pthread_mutex_unlock(&li->li_root_mutex);
+		}
+
+		Debug( LDAP_DEBUG_ANY, "add: could not lock entry\n",
+			0, 0, 0 );
+
+		entry_free(e);
+
+		send_ldap_result( conn, op, LDAP_OPERATIONS_ERROR, "", "" );
+		return( -1 );
+	}
+
+	e->e_id = next_id( be );
+
 	/*
-	 * Try to add the entry to the cache, assign it a new dnid
-	 * and mark it locked.  This should only fail if the entry
-	 * already exists.
+	 * Try to add the entry to the cache, assign it a new dnid.
+	 * This should only fail if the entry already exists.
 	 */
 
-	e->e_id = next_id( be );
 	if ( cache_add_entry_lock( &li->li_cache, e, ENTRY_STATE_CREATING ) != 0 ) {
 		if( p != NULL) {
 			/* free parent and writer lock */
@@ -144,17 +165,13 @@ ldbm_back_add(
 		    0 );
 		next_id_return( be, e->e_id );
                 
-		/* XXX this should be ok, no other thread should have access
-		 * because e hasn't been added to the cache yet
-		 */
+		entry_rdwr_unlock(e, 1);;
 		entry_free( e );
+
 		send_ldap_result( conn, op, LDAP_ALREADY_EXISTS, "", "" );
 		return( -1 );
 	}
 
-	/* acquire writer lock */
-	entry_rdwr_lock(e, 1);
-
 	/*
 	 * add it to the id2children index for the parent
 	 */