From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 5 May 2001 20:39:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 5 May 2001 20:38:51 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:40308 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Sat, 5 May 2001 20:38:36 -0400 Date: Sun, 6 May 2001 02:37:23 +0200 From: Andrea Arcangeli To: Chris Wedgwood Cc: Jens Axboe , Rogier Wolff , Linus Torvalds , Alan Cox , volodya@mindspring.com, Alexander Viro , linux-kernel@vger.kernel.org Subject: Re: [PATCH] SMP race in ext2 - metadata corruption. Message-ID: <20010506023723.A22850@athlon.random> In-Reply-To: <200105041140.NAA03391@cave.bitwizard.nl> <20010504135614.S16507@suse.de> <20010504172940.U3762@athlon.random> <20010505151808.A29451@metastasis.f00f.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010505151808.A29451@metastasis.f00f.org>; from cw@f00f.org on Sat, May 05, 2001 at 03:18:08PM +1200 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 05, 2001 at 03:18:08PM +1200, Chris Wedgwood wrote: > On Fri, May 04, 2001 at 05:29:40PM +0200, Andrea Arcangeli wrote: > > once block_dev is in pagecache there will obviously be no-way to > share cache between the block device and the filesystem, because > all the caches will be in completly different address spaces. > > Once we are at this point... will there be any use in having block > devices? FreeBSD appears to have done without them completely about a moving block_dev in pagecache won't change anything from userspace point of view, it's a transparent change (if we ignore the total loss of cache coherency between block_dev and fs metadata that it implies, but as Linus said such loss of coherency will happen anyways eventually because metadata will go into its address space too). Basically there will still be a use for the block devices as far as there are fsck and other userspace applications that want to use it. Andrea SYNAPSE (very amusing movie ;)