From owner-freebsd-fs@FreeBSD.ORG  Sat Dec 27 22:01:30 2014
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 30163433;
 Sat, 27 Dec 2014 22:01:30 +0000 (UTC)
Received: from chez.mckusick.com (chez.mckusick.com
 [IPv6:2001:5a8:4:7e72:4a5b:39ff:fe12:452])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 1014064DE1;
 Sat, 27 Dec 2014 22:01:30 +0000 (UTC)
Received: from chez.mckusick.com (localhost [127.0.0.1])
 by chez.mckusick.com (8.14.3/8.14.3) with ESMTP id sBRM1QYp062205;
 Sat, 27 Dec 2014 14:01:27 -0800 (PST)
 (envelope-from mckusick@chez.mckusick.com)
Message-Id: <201412272201.sBRM1QYp062205@chez.mckusick.com>
To: Rick Macklem <rmacklem@uoguelph.ca>
Subject: Re: RFC: new NFS mount option or restore old behaviour for Solaris
 server bug? 
In-reply-to: <1190766207.2826601.1419690496079.JavaMail.root@uoguelph.ca> 
Date: Sat, 27 Dec 2014 14:01:26 -0800
From: Kirk McKusick <mckusick@mckusick.com>
Cc: FreeBSD Filesystems <freebsd-fs@freebsd.org>,
 Konstantin Belousov <kib@freebsd.org>
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs/>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 27 Dec 2014 22:01:30 -0000

> Date: Sat, 27 Dec 2014 09:28:16 -0500 (EST)
> From: Rick Macklem <rmacklem@uoguelph.ca>
> To: FreeBSD Filesystems <freebsd-fs@freebsd.org>,
>         John Baldwin <jhb@freebsd.org>, Konstantin Belousov <kib@freebsd.org>
> Subject: RFC: new NFS mount option or restore old behaviour for Solaris
>  server bug?
> 
> Hi,
> 
> The FreeBSD9.1 and earlier NFS clients almost always (unless the
> tod clock ticked to next second while the operation was in progress)
> set the mtime to the server's time (xx_TOSERVER) for exclusive open.
> Starting with FreeBSD9.2, the mtime would be set to the client's time
> due to r245508, which fixed the code for utimes() to use VA_UTIMES_NULL.
> 
> This change tickled a bug in recent Solaris servers, which return
> NFS_OK to the Setattr RPC but don't actually set the file's mode bits.
> (The bug isn't tickled when mtime is set to the server's time.)
> I have patches to work around this in two ways:
> 1 - Add a new "useservertime" mount option that forces xx_TOSERVER.
>     (This patch would force xx_TOSERVER for exclusive open.)
>     It permits the man page to document why it is needed-->broken Solaris servers.
> 2 - Use xx_TOSERVER for exclusive open always. Since this was the normal
>     behaviour until FreeBSD9.2, I don't think this would cause problems or
>     be a POLA violation, but I can't be sure?
> 
> I am leaning towards #2, since it avoids yet another mount option.
> However, I'd like other people's opinions on which option is better,
> or any other suggestions?
> 
> Thanks in advance for your comments, rick

I lean towards solution #2. It tracks historic practice and avoids
yet another mount flag.

	Kirk McKusick