From: Frank van Maarseveen Subject: Re: [NFS] Disabling Symbolic Link Content Caching in NFS Client Date: Tue, 3 Jun 2003 16:46:56 +0200 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <20030603144656.GA6157@iapetus.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Edward Hibbert Return-path: To: nfs@lists.sourceforge.net, linux-kernel@vger.kernel.org In-Reply-To: List-ID: On Tue, Jun 03, 2003 at 02:33:45PM +0100, Edward Hibbert wrote: > > Our application consists of a number of machines collaborating on a shared > database over NFS. We therefore require the ability to force data to be > sync'd from the client to the backend - and at the moment we do this by > disabling caching completely, via the noac option and acquiring and > releasing non-exclusive locks round io calls. > > Any improvements in the granularity of control over NFS client-side caching > would be very valuable to us. To disable ac for a single directory for a certain amount of time, see http://web.inter.nl.net/users/fvm/nfs-noac/2.4.20-noac-timeout.patch http://web.inter.nl.net/users/fvm/nfs-noac/readme: This patch implements /proc/sys/net/nfs/noac-timeout When a nonzero value is written, suspend atribute caching for the current working directory and one level of files inside for the specified number of seconds. Attribute caching will automatically be enabled when the time elapses. Writing a zero re-enables attribute caching as well. Reading yields the number of remaining seconds attribute caching will be disabled. Maybe an NFS specific ioctl would be cleaner. But the above patch can be used even from simple scripts. -- Frank