From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:21218 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622Ab2K0OYA (ORCPT ); Tue, 27 Nov 2012 09:24:00 -0500 Message-ID: <50B4CCFD.6010900@RedHat.com> Date: Tue, 27 Nov 2012 09:23:57 -0500 From: Steve Dickson MIME-Version: 1.0 To: "J. Bruce Fields" CC: Chuck Lever , linux-nfs@vger.kernel.org Subject: Re: [PATCH] Revert "mountd: handle allocation failures in auth_unix_ip upcall" References: <20121126220343.GA18140@fieldses.org> <73EFE585-98D4-40BE-9EDF-15CC6B14BDB2@oracle.com> <20121126221535.GB18186@fieldses.org> <20121126225116.GE18186@fieldses.org> In-Reply-To: <20121126225116.GE18186@fieldses.org> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: Hello, On 26/11/12 17:51, J. Bruce Fields wrote: >> What exactly is the problem with the current code? >> > >> > client_resolve() can return a NULL in some cases. Why is it OK to >> > pass a NULL "ai" to client_compose() ? Looks like that can result in >> > a mountd segfault. > Bah, I thought I'd checked this and found it was prepared to handle > that, but no: > > client_check->check_wildcard() > > looks like it can oops. Yeah... added client_check->check_netgroup() to this list... > > OK, I'll take another look. A simply check that ai is not null when calling client_compose() should work.. > >> > The kernel won't get any downcall reply in that >> > case! Is that what you are trying to fix? >> > >> > WRT my original objection: In general I don't see how to make it >> > impossible for mountd to fail. > Sure, but mountd is required for the server to function, so it's just a > question of how we fail. > >> > Thus the kernel needs to be better about recovering when mountd >> > suddenly disappears. > Currently it drops and lets the client retry. I suspect that's the > correct thing to do, but alternatives are welcomed. This one things I didn't see happen... the client retrying... expected it would... steved.