From: Jeff Layton <jlayton@redhat.com>
Subject: Re: [NFS] What's slated for inclusion in 2.6.24-rc1 from the NFS
	client git tree...
Date: Fri, 5 Oct 2007 14:12:22 -0400
Message-ID: <20071005141222.5afbb6b9.jlayton@redhat.com>
References: <1191454876.6726.32.camel@heimdal.trondhjem.org>
	<20071004085206.0a8e37b5@poseidon.drzeus.cx>
	<1191506450.6685.17.camel@heimdal.trondhjem.org>
	<30494.1191605410@turing-police.cc.vt.edu>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Cc: Andrew@linux-nfs.org, nfsv4@linux-nfs.org,
	linux-kernel@vger.kernel.org, nfs@lists.sourceforge.net,
	Pierre Ossman <drzeus-list@drzeus.cx>,
	Morton <akpm@linux-foundation.org>
To: Valdis.Kletnieks@vt.edu
In-Reply-To: <30494.1191605410@turing-police.cc.vt.edu>
Sender: nfsv4-bounces@linux-nfs.org
Errors-To: nfsv4-bounces@linux-nfs.org

On Fri, 05 Oct 2007 13:30:10 -0400
Valdis.Kletnieks@vt.edu wrote:

> On Thu, 04 Oct 2007 10:00:50 EDT, Trond Myklebust said:
> 
> > How about a boot/module parameter to turn it on or off?
> > 
> > I don't see any point in having a sysctl for something like this: either
> > you have legacy applications or you don't. It is not something that you
> > switch off as you go off to lunch.
> 
> How does Joe Sysadmin tell if he has an affected legacy app or not?
> 
> (The obvious "try it and see what breaks" is a non-starter for many places,
> because you too easily end up in a loop of "enable it, find 4-5 show stoppers,
> turn it off, fix them, lather rinse repease".  Been there, done that, got
> the tshirt - a project I got dragged into involves a large storage array that
> appears to insist on exporting 64-bit stuff, and a large farm of clients that
> are very 64-bit unclean....)
> 

Note that "try it and see what breaks" isn't reliable either. If glibc
gets back a 64 bit inode number that just happens to fit in the 32-bit
field, then everything will work. You don't actually get an EOVERFLOW
until st_ino overflows the field, and that may not happen often enough
for testing this way to detect it...


-- 
Jeff Layton <jlayton@redhat.com>