Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:52400 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751040AbdJLOVK (ORCPT ); Thu, 12 Oct 2017 10:21:10 -0400 Subject: Re: [PATCH] nfs(5): update some version information To: "J. Bruce Fields" Cc: linux-nfs@vger.kernel.org References: <20171011160243.GG25913@fieldses.org> From: Steve Dickson Message-ID: <93f59205-adaa-2794-f3a3-e604c33ef1f1@RedHat.com> Date: Thu, 12 Oct 2017 10:21:09 -0400 MIME-Version: 1.0 In-Reply-To: <20171011160243.GG25913@fieldses.org> Content-Type: text/plain; charset=utf-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 10/11/2017 12:02 PM, J. Bruce Fields wrote: > From: "J. Bruce Fields" > > We've seen some confusion from people not understanding why newer > clients may not support NFSv2. It might help a little to note in the > man page that version support depends on how the kernel was built. > > While we're there: > > - update some references to NFS protocol versions. > - update 4.0 RFC, and add references to 4.1 and 4.2 RFCs. > - rename "BUGS" to "NOTES"; the section mostly isn't about bugs. > (Might be time to remove some of the linux-2.4 notes too.) > - remove some outdated references to optional NFSv4+ features. > (Or should we try to keep this information up to date?) > > Signed-off-by: J. Bruce Fields Committed... steved. > --- > utils/mount/nfs.man | 35 ++++++++++++++++++++--------------- > 1 file changed, 20 insertions(+), 15 deletions(-) > > diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man > index 7d42f19d0ca6..bd1508c6154d 100644 > --- a/utils/mount/nfs.man > +++ b/utils/mount/nfs.man > @@ -11,11 +11,8 @@ NFS is an Internet Standard protocol > created by Sun Microsystems in 1984. NFS was developed > to allow file sharing between systems residing > on a local area network. > -The Linux NFS client supports three versions > -of the NFS protocol: > -NFS version 2 [RFC1094], > -NFS version 3 [RFC1813], > -and NFS version 4 [RFC3530]. > +Depending on kernel configuration, the Linux NFS client may > +support NFS versions 2, 3, 4.0, 4.1, or 4.2. > .P > The > .BR mount (8) > @@ -88,9 +85,8 @@ These options are valid to use with any NFS version. > The NFS protocol version number used to contact the server's NFS service. > If the server does not support the requested version, the mount request > fails. > -If this option is not specified, the client negotiates a suitable version > -with > -the server, trying version 4 first, version 3 second, and version 2 last. > +If this option is not specified, the client tries version 4.2 first, > +then negotiates down until it finds a version supported by the server. > .TP 1.5i > .BI vers= n > This option is an alternative to the > @@ -762,7 +758,7 @@ NOTE: When used together, the 'local_lock' mount option will be overridden > by 'nolock'/'lock' mount option. > .SS "Options for NFS version 4 only" > Use these options, along with the options in the first subsection above, > -for NFS version 4 and newer. > +for NFS version 4.0 and newer. > .TP 1.5i > .BI proto= netid > The > @@ -835,7 +831,7 @@ the behavior of this option in more detail. > Specifies a single IPv4 address (in dotted-quad form), > or a non-link-local IPv6 address, > that the NFS client advertises to allow servers > -to perform NFS version 4 callback requests against > +to perform NFS version 4.0 callback requests against > files on this mount point. If the server is unable to > establish callback connections to clients, performance > may degrade, or accesses to files may temporarily hang. > @@ -848,6 +844,11 @@ In the presence of multiple client network interfaces, > special routing policies, > or atypical network topologies, > the exact address to use for callbacks may be nontrivial to determine. > +.IP > +NFS protocol versions 4.1 and 4.2 use the client-established > +TCP connection for callback requests, so do not require the server to > +connect to the client. This option is therefore only affect NFS version > +4.0 mounts. > .TP 1.5i > .BR migration " / " nomigration > Selects whether the client uses an identification string that is compatible > @@ -1789,7 +1790,7 @@ file system table > .TP 1.5i > .I /etc/nfsmount.conf > Configuration file for NFS mounts > -.SH BUGS > +.SH NOTES > Before 2.4.7, the Linux NFS client did not support NFS over TCP. > .P > Before 2.4.20, the Linux NFS client used a heuristic > @@ -1808,9 +1809,9 @@ when the > .BR rsize " and " wsize > settings were smaller than the system's page size. > .P > -The Linux NFS client does not yet support > -certain optional features of the NFS version 4 protocol, > -such as security negotiation, server referrals, and named attributes. > +The Linux client's support for protocol versions depend on whether the > +kernel was built with options CONFIG_NFS_V2, CONFIG_NFS_V3, > +CONFIG_NFS_V4, CONFIG_NFS_V4_1, and CONFIG_NFS_V4_2. > .SH "SEE ALSO" > .BR fstab (5), > .BR mount (8), > @@ -1843,4 +1844,8 @@ RFC 1833 for the RPC bind specification. > .br > RFC 2203 for the RPCSEC GSS API protocol specification. > .br > -RFC 3530 for the NFS version 4 specification. > +RFC 7530 for the NFS version 4.0 specification. > +.br > +RFC 5661 for the NFS version 4.1 specification. > +.br > +RFC 7862 for the NFS version 4.2 specification. >