From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 22 Jun 2001 03:44:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 22 Jun 2001 03:44:32 -0400 Received: from d12lmsgate-3.de.ibm.com ([195.212.91.201]:18064 "EHLO d12lmsgate-3.de.ibm.com") by vger.kernel.org with ESMTP id ; Fri, 22 Jun 2001 03:44:25 -0400 From: Stefan.Bader@de.ibm.com X-Lotus-FromDomain: IBMDE To: Chris Mason , Andrea Arcangeli , Linus Torvalds cc: linux-kernel@vger.kernel.org Message-ID: Date: Fri, 22 Jun 2001 09:43:54 +0200 Subject: Re: correction: fs/buffer.c underlocking async pages Mime-Version: 1.0 Content-type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Chris Mason 06/21/01 08:20 PM Please respond to Chris Mason To: Andrea Arcangeli , Linus Torvalds cc: Stefan Bader/Germany/IBM@IBMDE, linux-kernel@vger.kernel.org Subject: Re: correction: fs/buffer.c underlocking async pages On Thursday, June 21, 2001 07:15:22 PM +0200 Andrea Arcangeli wrote: >> On Thu, Jun 21, 2001 at 09:56:04AM -0700, Linus Torvalds wrote: >> What's the problem with the existing code, and why do people want to add >> a >>> (unnecessary) new bit? >> >> there's no problem with the existing code, what I understood is that >> they cannot overwrite the ->b_end_io callback in the lowlevel blkdev >> layer or the page will be unlocked too early. >Just to be more explicit, the big problem is mixing different async >callbacks on the same page. The patch would also allow things like this: > >fs_specific_end_io() { > do something special > end_buffer_io_async() >} > >-chris Yes, that was exactly the thing I tried to do. In my case some sort of bookkeeping how many IO's where mapped (to a certain path) and how many came back. My assumption first was, if I am restoring the old pointers before I call the original function it should work. After running into problems this patch was just my quick hack to try out whether this was the only place that I did not think of. I wouldn't insist on the exact way to do it, but since it worked for me, I thought it might be worth to discuss (or even be useful for other people... ;-)). - Stefan Linux for eServer development Stefan.Bader@de.ibm.com Phone: +49 (7031) 16-2472 ---------------------------------------------------------------------------------- When all other means of communication fail, try words.