Return-Path: Anna.Schumaker@netapp.com Message-ID: <54622ADF.4080807@Netapp.com> Date: Tue, 11 Nov 2014 10:27:27 -0500 From: Anna Schumaker MIME-Version: 1.0 To: Benjamin Coddington , Trond Myklebust CC: Linux NFS Mailing List Subject: Re: mount default minor version behavior References: In-Reply-To: Content-Type: text/plain; charset="utf-8" List-ID: Hi Ben, On 11/11/2014 10:20 AM, Benjamin Coddington wrote: > > On Tue, 11 Nov 2014, Trond Myklebust wrote: > >> Hi Ben, >> >> On Tue, Nov 11, 2014 at 9:39 AM, Benjamin Coddington >> wrote: >>> I will update mount.nfs so the default version is 4.1. I have two quick >>> questions on desired behavior: >>> >>> o Should mounts that do not specify a minor version be upgraded to the >>> default minor version? >>> >>> For example, should 'mount -overs=4' turn into 'mount -overs4.1', if the >>> current default is 4.1? >>> >>> >>> o If 'yes' to the above, should mount auto-retry decrementing minor >>> versions if EPROTONOSUPPORT? >>> >>> For example, 'mount -overs=4' with a default of 4.2 would attempt: 4.2, >>> then 4.1, then 4.0. >>> >> One thing you should note when doing this: the current parser for >> /etc/nfsmount.conf does not support minor versions. I think it needs >> to, so that we can continue to use it to set defaults. >> >> ...and to answer your questions above, I think that we should be able >> to specify a 'default nfsv4 minor version' in /etc/nfsmount.conf, and >> then negotiate down from there. >> IOW: extend the 'Defaultvers' and 'Nfsvers' options to support 4.0, >> 4.1, 4.2,.... > Ah, good idea to make it configurable. > >> The result should be that If I do 'mount -t nfs' with no '-overs' >> option, then we start at 4.1 (if that is the default in >> /etc/nfsmount.conf) and then try 4.0, 3, 2 in that order. >> If I do 'mount -t nfs -overs=4', then again consult /etc/nfsmount.conf; >> - if there is a default matching a v4 minor version, then start at >> that and negotiate down (but stop at 4.0). > Yep, those closely match the current behavior and that's what my first > pass looks like. > >> - if there is no default in /etc/nfsmount.conf, then perhaps assume a >> default of 0(????) > That's the question, and I think it will be a very common case. Do we > want to have an idea of a "best" minor version, and use that if no minor > version is specified? I don't think so. Right now users know that if they don't use a minor version then they'll be getting a v4.0 mount. I think we should keep this behavior so we don't accidentally break people's configuration. Anna > > Ben > >> Cheers >> Trond >> >> >> -- >> Trond Myklebust >> >> Linux NFS client maintainer, PrimaryData >> >> trond.myklebust@primarydata.com >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html