Import entry_rwlock() call reordering to remove race condition.

[openldap] / servers / slapd / back-ldbm / add.c

diff --git a/servers/slapd/back-ldbm/add.c b/servers/slapd/back-ldbm/add.c
index 6faaf948f30cbfcb741b81e47e1336edb919c060..713372f24d5486b76c3cc45d57a75d541553c40b 100644 (file)
--- a/servers/slapd/back-ldbm/add.c
+++ b/servers/slapd/back-ldbm/add.c
@@ -128,13 +128,35 @@ 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);
+               free( dn );
+
+               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 */
@@ -149,18 +171,14 @@ 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 );
                free( dn );
+
                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
         */