Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755211AbXAAOfk (ORCPT ); Mon, 1 Jan 2007 09:35:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755210AbXAAOfk (ORCPT ); Mon, 1 Jan 2007 09:35:40 -0500 Received: from hancock.steeleye.com ([71.30.118.248]:60699 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755208AbXAAOfj (ORCPT ); Mon, 1 Jan 2007 09:35:39 -0500 Subject: Re: fuse, get_user_pages, flush_anon_page, aliasing caches and all that again From: James Bottomley To: Linus Torvalds Cc: Russell King , Miklos Szeredi , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Andrew Morton In-Reply-To: References: <20061221152621.GB3958@flint.arm.linux.org.uk> <20061221171739.GE3958@flint.arm.linux.org.uk> <20061230163955.GA12622@flint.arm.linux.org.uk> <20061230165012.GB12622@flint.arm.linux.org.uk> Content-Type: text/plain Date: Mon, 01 Jan 2007 09:35:17 -0500 Message-Id: <1167662118.5302.52.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 (2.6.3-1.fc5.5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1433 Lines: 34 On Sat, 2006-12-30 at 10:26 -0800, Linus Torvalds wrote: > > On Sat, 30 Dec 2006, Russell King wrote: > > > > And here's the flush_anon_page() part. This looks fine to me (if you need my ack). > > Add flush_anon_page() for ARM, to avoid data corruption issues when using > > fuse or other subsystems using get_user_pages(). > > Btw, since this doesn't actually change any code for anybody but ARM, just > adds a parameter that is obviously unused by everybody else, and if it > actually fixes a real bug for ARM, I'll obviously happily take it even > before 2.6.20. So go ahead put it in your ARM tree, and we'll get some > testing through that. And just ask me to pull at some point. > > I wonder why nobody else seems to have a "flush_anon_page()"? This would > seem to be a potential issue for architectures like sparc too.. Although > maybe sparc can do a flush by physical index with "flush_dcache_page()". The sparc handling of anonymous pages is different ... they accitentally sweep them up in flush_dcache_page(). When I audited the architectures to try to make fuse work on parisc, parisc and arm were the only ones that actually needed flush_anon_page(). James - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/