don't dereference NULL pointers

[openldap] / servers / slapd / back-bdb / idl.c

diff --git a/servers/slapd/back-bdb/idl.c b/servers/slapd/back-bdb/idl.c
index 35d6d4890d4d228f5fb6f51a262e6621b7997f79..ff85ecee5cdbe683e8bf819ea54f4011bc23717a 100644 (file)
--- a/servers/slapd/back-bdb/idl.c
+++ b/servers/slapd/back-bdb/idl.c
@@ -2,7 +2,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2007 The OpenLDAP Foundation.
+ * Copyright 2000-2008 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -27,11 +27,24 @@
 
 #define IDL_CMP(x,y)   ( x < y ? -1 : ( x > y ? 1 : 0 ) )
 
-#define IDL_LRU_DELETE( bdb, e ) do {                                  \
-       if ( e == bdb->bi_idl_lru_head ) bdb->bi_idl_lru_head = e->idl_lru_next; \
-       if ( e == bdb->bi_idl_lru_tail ) bdb->bi_idl_lru_tail = e->idl_lru_prev; \
-       e->idl_lru_next->idl_lru_prev = e->idl_lru_prev; \
-       e->idl_lru_prev->idl_lru_next = e->idl_lru_next; \
+#define IDL_LRU_DELETE( bdb, e ) do { \
+       if ( (e) == (bdb)->bi_idl_lru_head ) { \
+               if ( (e)->idl_lru_next == (bdb)->bi_idl_lru_head ) { \
+                       (bdb)->bi_idl_lru_head = NULL; \
+               } else { \
+                       (bdb)->bi_idl_lru_head = (e)->idl_lru_next; \
+               } \
+       } \
+       if ( (e) == (bdb)->bi_idl_lru_tail ) { \
+               if ( (e)->idl_lru_prev == (bdb)->bi_idl_lru_tail ) { \
+                       assert( (bdb)->bi_idl_lru_head == NULL ); \
+                       (bdb)->bi_idl_lru_tail = NULL; \
+               } else { \
+                       (bdb)->bi_idl_lru_tail = (e)->idl_lru_prev; \
+               } \
+       } \
+       (e)->idl_lru_next->idl_lru_prev = (e)->idl_lru_prev; \
+       (e)->idl_lru_prev->idl_lru_next = (e)->idl_lru_next; \
 } while ( 0 )
 
 static int
@@ -349,6 +362,10 @@ bdb_idl_cache_put(
        ldap_pvt_thread_mutex_lock( &bdb->bi_idl_tree_lrulock );
        /* LRU_ADD */
        if ( bdb->bi_idl_lru_head ) {
+               assert( bdb->bi_idl_lru_tail != NULL );
+               assert( bdb->bi_idl_lru_head->idl_lru_prev != NULL );
+               assert( bdb->bi_idl_lru_head->idl_lru_next != NULL );
+
                ee->idl_lru_next = bdb->bi_idl_lru_head;
                ee->idl_lru_prev = bdb->bi_idl_lru_head->idl_lru_prev;
                bdb->bi_idl_lru_head->idl_lru_prev->idl_lru_next = ee;
@@ -362,8 +379,11 @@ bdb_idl_cache_put(
        if ( ++bdb->bi_idl_cache_size > bdb->bi_idl_cache_max_size ) {
                int i;
                ee = bdb->bi_idl_lru_tail;
-               for ( i = 0; i < 10; i++, ee = eprev ) {
+               for ( i = 0; ee != NULL && i < 10; i++, ee = eprev ) {
                        eprev = ee->idl_lru_prev;
+                       if ( eprev == ee ) {
+                               eprev = NULL;
+                       }
                        if ( ee->idl_flags & CACHE_ENTRY_REFERENCED ) {
                                ee->idl_flags ^= CACHE_ENTRY_REFERENCED;
                                continue;
@@ -382,6 +402,8 @@ bdb_idl_cache_put(
                        ch_free( ee );
                }
                bdb->bi_idl_lru_tail = eprev;
+               assert( bdb->bi_idl_lru_tail != NULL
+                       || bdb->bi_idl_lru_head == NULL );
        }
        ldap_pvt_thread_mutex_unlock( &bdb->bi_idl_tree_lrulock );
        ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
@@ -480,7 +502,7 @@ int
 bdb_idl_fetch_key(
        BackendDB       *be,
        DB                      *db,
-       BDB_LOCKER locker,
+       DB_TXN          *txn,
        DBT                     *key,
        ID                      *ids,
        DBC                     **saved_cursor,
@@ -553,13 +575,12 @@ bdb_idl_fetch_key(
 
        /* If we're not reusing an existing cursor, get a new one */
        if( opflag != DB_NEXT ) {
-               rc = db->cursor( db, NULL, &cursor, bdb->bi_db_opflags );
+               rc = db->cursor( db, txn, &cursor, bdb->bi_db_opflags );
                if( rc != 0 ) {
                        Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
                                "cursor failed: %s (%d)\n", db_strerror(rc), rc, 0 );
                        return rc;
                }
-               CURSOR_SETLOCKER( cursor, locker );
        } else {
                cursor = *saved_cursor;
        }
@@ -693,10 +714,6 @@ bdb_idl_insert_key(
 
        assert( id != NOID );
 
-       if ( bdb->bi_idl_cache_size ) {
-               bdb_idl_cache_del( bdb, db, key );
-       }
-
        DBTzero( &data );
        data.size = sizeof( ID );
        data.ulen = data.size;
@@ -869,6 +886,12 @@ fail:
                cursor->c_close( cursor );
                return rc;
        }
+       /* If key was added (didn't already exist) and using IDL cache,
+        * update key in IDL cache.
+        */
+       if ( !rc && bdb->bi_idl_cache_max_size ) {
+               bdb_idl_cache_add_id( bdb, db, key, id );
+       }
        rc = cursor->c_close( cursor );
        if( rc != 0 ) {
                Debug( LDAP_DEBUG_ANY, "=> bdb_idl_insert_key: "
@@ -901,7 +924,7 @@ bdb_idl_delete_key(
        }
        assert( id != NOID );
 
-       if ( bdb->bi_idl_cache_max_size ) {
+       if ( bdb->bi_idl_cache_size ) {
                bdb_idl_cache_del( bdb, db, key );
        }