From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: Re: [PATCH 4/5] NFS: set transport defaults after mount option parsing is finished Date: Thu, 12 Jun 2008 12:57:37 -0400 Message-ID: <1213289857.14478.10.camel@localhost> References: <20080612163416.13197.92911.stgit@manray.1015granger.net> <20080612163756.13197.37893.stgit@manray.1015granger.net> Mime-Version: 1.0 Content-Type: text/plain Cc: linux-nfs@vger.kernel.org To: Chuck Lever Return-path: Received: from mx2.netapp.com ([216.240.18.37]:53088 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752224AbYFLQ5k (ORCPT ); Thu, 12 Jun 2008 12:57:40 -0400 In-Reply-To: <20080612163756.13197.37893.stgit-meopP2rzCrTwdl/1UfZZQIVfYA8g3rJ/@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 2008-06-12 at 12:37 -0400, Chuck Lever wrote: > Address some unfortunate mount option parsing behavior by setting certain > transport-based defaults *after* option parsing is complete. > > o Some options don't obey the "rightmost wins" rule. Jeff Layton > noticed that specifying the "proto=" mount option after the "retrans" > or "timeo" options will cause the retrans and timeo values to be > overwritten with default settings. > > Allow these options to be specified in any order without unexpectedly > reverting retrans and timeo to their default. > > o I've received several reports that text-based mounting through > firewalls that block UDP fails, even if "proto=tcp" is specified. > > If a user specifies "proto=tcp" via the legacy mount API, the mount > command also uses TCP to contact the server's mount daemon. Ditto > for "proto=udp". We want the kernel's mount option to emulate this > behavior; however, we still want the default mount protocol to be UDP > if no transport options were specified. Why is it necessary to set these defaults in nfs_parse_mount_options? This is quite unrelated to parsing of the mount string. -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com