From: Chuck Lever Subject: Re: The text-based mount interface doesn't support -s (--sloppy) Date: Fri, 25 Apr 2008 11:17:39 -0400 Message-ID: <82AA941E-B77C-40FF-8021-3E3950AA7D45@oracle.com> References: <20080425081114.GA5148@uio.no> <20080425143543.GA6292@uio.no> <54BFCFD6-18D0-42E9-ADE9-867BEB1B2AB5@oracle.com> <20080425110319.479a0e80@tupile.poochiereds.net> Mime-Version: 1.0 (Apple Message framework v919.2) Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Cc: "Steinar H. Gunderson" , Linux NFS Mailing List To: Jeff Layton Return-path: Received: from agminet01.oracle.com ([141.146.126.228]:42736 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751869AbYDYPSO (ORCPT ); Fri, 25 Apr 2008 11:18:14 -0400 In-Reply-To: <20080425110319.479a0e80-PC62bkCOHzGdMjc06nkz3ljfA9RmPOcC@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Apr 25, 2008, at 11:03 AM, Jeff Layton wrote: > On Fri, 25 Apr 2008 10:50:09 -0400 > Chuck Lever wrote: > >> On Apr 25, 2008, at 10:35 AM, Steinar H. Gunderson wrote: >>> On Fri, Apr 25, 2008 at 10:30:35AM -0400, Chuck Lever wrote: >>>> It's not exactly clear what the "sloppy" option is supposed to >>>> allow. >>>> We are trying to figure out right now precisely how this should >>>> work. >>> >>> Well, in general it seems to ignore any new options that come into >>> it. The >>> problem in question was -o grpid= that was coming in through autofs >>> mounts and was not too easy to remove for the user. >> >> The grpid mount option is what triggered our earlier discussion of -- >> sloppy as well. >> >> An expedient solution may be to tell the kernel mount option parser >> specifically to ignore these common automounter options, like grpid. >> Jeff, what do you think of that? >> > > That might reduce the pain for now... > > I tend to think the big problem is people sharing autofs maps between > different OS's. It's hard to predict what options we might see that > are > valid on another OS. We really need to define what the sloppy flag > means and how it behaves. It's a reasonably safe assumption that > autofs > will use it, so hooking that up is probably the best solution. > > Personally, I like the idea of just adding a "sloppy" mount option and > making "-s" add it to the string. When someone adds that option, the > kernel could just skip over options it doesn't recognize. When it's > not > present, then it would fail on any unrecognized options. > > This might mean that we need to have the kernel parser do more than > one > pass over the string though. Once to look for the sloppy option, and > again to parse the others. This is not such a bad thing, IMO...there > are some other options that can get clobbered depending on order. The mount.nfs command can easily guarantee that the "sloppy" option comes first. It might be a nice added flexibility to allow the parser to switch from strict to sloppy mode in the middle of the option string. > For instance, if retrans or timeo is parsed before "tcp" those options > can get overwritten. We may end up needing a multi-pass parser > anyway... The parser can be made more careful about how those options are handled. -- Chuck Lever chuck[dot]lever[at]oracle[dot]com