Return-Path: Received: from mail-out1.uio.no ([129.240.10.57]:33562 "EHLO mail-out1.uio.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751707AbZAFNFF (ORCPT ); Tue, 6 Jan 2009 08:05:05 -0500 Subject: Re: [RFC][PATCH 4/4] Represent RPC Callers From: Trond Myklebust To: Matt Helsley Cc: Linux Containers , "J. Bruce Fields" , Cedric Le Goater , Linux Kernel Mailing List , linux-nfs@vger.kernel.org, Chuck Lever , "Eric W. Biederman" , Linux Containers In-Reply-To: <20090106011315.229045829@us.ibm.com> References: <20090106011314.534653345@us.ibm.com> <20090106011315.229045829@us.ibm.com> Content-Type: text/plain Date: Tue, 06 Jan 2009 08:04:22 -0500 Message-Id: <1231247062.7127.36.camel@heimdal.trondhjem.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Mon, 2009-01-05 at 17:13 -0800, Matt Helsley wrote: > plain text document attachment (move-rpc-client-nodename-cache.patch) > Currently RPC needs to know the nodename (often the same as the hostname) which > should be used for UNIX-style authentication and file-lock tracking. Because > hostname can change between RPC calls and some sequences of RPC calls may > require consistent names between calls RPC currently saves the nodename with > the RPC client structure. > > This is doesn't always work because RPC clients may be discarded over the > lifetime of a higher level service -- like those that compose NFS. Specifically > this is known to happen during shutdown. > > Hence RPC should expect the nodename to be saved by the caller when sequences > of RPC calls requiring consistent nodenames may be needed (e.g. NFS). To enable > this we introduce an RPC caller structure that allows RPC to query the caller > for this information. > > This patch is not complete but is meant to indicate the direction I'm planning > on going. I'd like to know if there are any objections or if anyone sees a > better way to handle this. You're planning on slowing down every RPC call in order to fix a problem on client shutdown? Why? Trond