From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262814AbVAFNE2 (ORCPT ); Thu, 6 Jan 2005 08:04:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262817AbVAFNE2 (ORCPT ); Thu, 6 Jan 2005 08:04:28 -0500 Received: from mx1.redhat.com ([66.187.233.31]:51332 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262814AbVAFNEY (ORCPT ); Thu, 6 Jan 2005 08:04:24 -0500 From: David Howells In-Reply-To: <20050106113216.GA16261@infradead.org> References: <20050106113216.GA16261@infradead.org> <20050103011113.6f6c8f44.akpm@osdl.org> <20050103100725.GA17856@infradead.org> To: Christoph Hellwig Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: 2.6.10-mm1 X-Mailer: MH-E 7.82; nmh 1.0.4; GNU Emacs 21.3.50.1 Date: Thu, 06 Jan 2005 13:04:04 +0000 Message-ID: <27229.1105016644@redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig wrote: > > > add-page-becoming-writable-notification.patch > > > Add page becoming writable notification > > > > David, this still has the bogus address_space operation in addition to > > the vm_operation. page_mkwrite only fits into the vm_operations scheme, > > so please remove the address_space op. Also the code will be smaller > > and faster witout that indirection.. > > Here's the fix: That's not right either. Filesystems really shouldn't be overloading the vm_ops on memory mappings (as has been made clear to me) and the VM low-level paging routines shouldn't be touching a_ops (as has also been made clear to me). I also have other reasons I don't want to have ordinary files with specialised vm_ops. I suppose I could try and build a little knowledge about fscache into the VM... that might be reasonable. Remember also that your change is going to affect NFS too eventually, assuming NFS caching support ends up being done this way. It may also affect other filesystems, such as SMB/CIFS and Coda eventually should they partake of fscache services too. David