From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Aneesh Kumar K.V" Subject: Re: [RFC] [PATCH] Inverse locking order of page_lock and transaction start Date: Mon, 7 Apr 2008 21:00:03 +0530 Message-ID: <20080407153003.GA20303@skywalker> References: <20080327162742.GC32534@duck.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from E23SMTP06.au.ibm.com ([202.81.18.175]:45485 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751813AbYDGPaa (ORCPT ); Mon, 7 Apr 2008 11:30:30 -0400 Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp06.au.ibm.com (8.13.1/8.13.1) with ESMTP id m37FU780014919 for ; Tue, 8 Apr 2008 01:30:07 +1000 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m37FYIW2263728 for ; Tue, 8 Apr 2008 01:34:18 +1000 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m37FUQiW011867 for ; Tue, 8 Apr 2008 01:30:26 +1000 Content-Disposition: inline In-Reply-To: <20080327162742.GC32534@duck.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Mar 27, 2008 at 05:27:42PM +0100, Jan Kara wrote: > Hi, > > below is the first version of the patch that reverses locking order of > page_lock and transaction start. I have tested it with fsx-linux, ltp DIO > tests etc. and lockdep didn't complain so hopefully I got it mostly right > but review is definitely needed. Especially I'd like to know what people > think about the way I've implemented ext3_page_mkwrite() - ext4 has > an incorrect code AFAICT because in ordered and journaled modes we should > write block of zeros and properly journal it (and no, block_page_mkwrite() > doesn't do it). We could implement ext3/4_page_mkwrite() in a similar way > we currently implement writepage calls but calling write_begin + write_end > does the job and should be only a tiny bit slower... > If nobody finds a serious flaw in the approach, I'll rediff the patch > against ext4 (I'll also try to convert delayed-alloc path - from a quick > look converting da_writepages path is going to be interesting). > I'm looking forward to your comments :) > I guess we should make this change first to Ext4 and then make the same to ext3. -aneesh