From: Kyle Rose <krose@krose.org>
Subject: Re: READDIRPLUS max mount option
Date: Fri, 07 Mar 2008 15:09:25 -0500
Message-ID: <47D1A0F5.2070501@krose.org>
References: <47D1995E.6060501@krose.org> <1204919978.16746.12.camel@heimdal.trondhjem.org>
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Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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To: Trond Myklebust <trond.myklebust@fys.uio.no>
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> The binary mount format is frozen forever, so the changes to nfs_mount.h
> and nfs4_mount.h are definitely NACKed.
>   
Ah. :-)  So is there no way to add mount options, or is there a 
different mechanism today?
> Otherwise, it would be nice to know why this absolutely has to be made a
> mount option rather than just having a system-wide option (either a
> module/boot parameter or a sysctl) to control the behaviour of all
> mounts.
>   
I mount multiple remote file systems.  Only one of them I own, so I'm 
willing to potentially hammer it with huge READDIRPLUS requests, while 
the others probably deserve more benign behavior. ;-)

In general, I think having system-wide defaults somewhere in proc is 
helpful---and certainly superior to a constant in the source---but there 
should really be mount-specific overrides wherever the system-wide 
default might not be globally appropriate.

Kyle